DISPLAYING GRAPHICAL OBJECTS

Description

[0001] The present invention relates to graphical user interfaces. Aspects of the present invention relate to a method of controlling the appearance of a graphical object in a graphical user interface. Aspects of the invention relate to a receiver/decoder, a television system, a computer program product, a computer readable medium and a signal. Aspects of the invention have a particular, but not exclusive, application in providing a graphical user interface for appliances such as receiver/decoders for digital television signals. However, aspects of the invention also have application to general purpose computers and other appliances.

[0002] Most graphical user interfaces (GUIs) include a similar set of basic components that can be manipulated by a user. These include such objects as push-buttons, sliders, list boxes, and so forth. Such components are referred to generically as "widgets". Although the basic function of widgets is common amongst many GUIs, the appearance of the widgets differs from one GUI to another.

[0003] Some graphical operating systems, the X window system for example, impose few constraints upon the appearance of widgets that can be displayed in the GUI. This allows programmers to develop applications using a number of different widget sets, each of which has its own distinctive appearance. Moreover, a large number of window managers run under X which influence the overall appearance of windows created by applications. Normally, it is possible to exercise some control over the appearance of an application as displayed on the GUI both during development of the application and to some extent at run time. However, the appearance is, in both cases, determined by hard coded parts of the widget set or the window manager. It is not possible for a user to change significantly the look of an application without re-coding the widget set, the window manager, or both. Either of these options requires a large amount of re-coding work and a large amount of new code to be installed on a host system.

[0004] One proposal to reduce the amount of re-coding work that must be done in order to update a look is to build elements (for example, corners, borders, and so forth) of a window in a GUI display from pixel maps stored in memory of a host system. This may be provided as an independent aspect of the invention. However, the pixel maps can occupy a significant amount of memory when in use, and represent a large amount of data to be transferred when the look is to be updated. This can be a significant disadvantage if the GUI must operate with limited resources and must be updated over a link of limited bandwidth. One example of such a situation arises when an application is executed on a receiver/decoder for digital television signals. Such a decoder has a limited amount of memory as compared with a general purpose computer, and the software (including the look of the GUI) is updated by downloading data from a channel which forms part of the received television signal.

[0005] "Generic View Handler Class," IBM Technical Disclosure Bulletin, vol. 34, no. 1, June 1991 (1991-06), pages 397-398. ISSN 0018-8689 describes an object-oriented view handler class that handles visual aspects for an object that is associated with it. EP 0798634 describes an apparatus and method for separating the design and implementation of a user interface from the design and implementation of the functional portion of a software program. Look and feel agents act as servers for logic objects. A look and feel agent controls the appearance and behaviour of the user interface, while logic objects perform the functions of the software program. Both solutions are limited in that they have problems when the view handler class is updated.

[0006] An aim of this invention is to provide an application developer with the ability to control the appearance of an application in a consistent and readily controllable manner, with a minimum of re-coding necessary, and with a minimum of data required to be transferred to an execution environment.

[0007] In a first aspect of the present invention there is provided a method of controlling the appearance of an object oriented widget in a graphical user interface, as defined in claim 1.

[0008] By explicitly defining a look object, rather than embedding code which controls appearance in an application, the invention may allow greater flexibility than hitherto in the way in which the appearance of a widget is controlled.

[0009] Preferably the look object includes code or parameters determining how the widget is displayed, such code or parameters preferably being stored in memory. For example, the look object may be defined by object-oriented program code.

[0010] The look object may be defined by instantiating a look object class. A look object which is defined in this way may contain a pointer to another look object class (other than that from which it is derived). This can allow the look object to access attributes and/or methods of that other look class. In this way, a look object can take its characteristics from two or more other looks, which can allow a look to be created which is the union of two different looks, or allow extra characteristics to be added to the look.

[0011] In order to associate the graphical object with the look object, the graphical object may include an attribute identifying the look object associated with the graphical object.

[0012] Preferably, the look object defines actual colours which are assigned to specific named colours. For example, the look object may define the actual colours which are assigned to at least one of black, white and one or several shades of grey. In this way, the look can define a certain colour scheme, for example, by giving a certain hue to graphical objects associated with that look. The look object may also define a colour map which sets the actual colour values which are to be used when displaying any particular colour.

[0013] In order to change the appearance of the widget , either the look object may be re-defined or modified (for example by changing the code or parameters at compile time, or the parameters at run time), or a different look object may be associated with the graphical object. The method may therefore further comprise modifying the appearance of the graphical object by re-defining or modifying the look object or by associating a different look object with the graphical object.

[0014] If a look object is re-defined or modified, then it may be necessary to update the appearance of graphical objects which are associated with that look object. In order to achieve this, the look object may include an update counter whose value is updated when the look object is re-defined or modified.

[0015] Preferably, graphical objects store the value of the update counter of the look object which they have affected. Each time a graphical object is to be redisplayed, the value stored by the graphical object is compared with the value of the update counter of the look object. If the two are different, the graphical object takes into account the modifications in the look object, and stores the new value of the update counter.

[0016] The look object may include a validation mask which indicates methods that can be called by the look object, so that methods which are not implemented by the look object are not called. The graphical object can access the validation mask of the look object to optimise the drawing of the graphical object. In this way, calls to methods which are not implemented can be avoided, which can speed up the drawing of the graphical object.

[0017] In some circumstances, for example when a look object is first created, the look object may be associated with a single graphical object. However, in preferred embodiments, the look object is associated with a plurality of graphical objects. By associating the look object with a plurality of graphical objects, a uniform appearance for those objects may be achieved, and the amount of data required for defining the look object may be reduced, in comparison to the case where each graphical object has its appearance defined independently.

[0018] Thus, the method may be a method of controlling the appearance of a plurality of graphical objects in a graphical user interface, and may comprise associating the look object with the plurality of graphical objects.

[0019] In certain situations, such as where no graphical objects are associated with a look object, it may be desirable to delete the look object, for example to enable the memory space used by the look object to be re-allocated. This may be particularly important in devices such as receiver/decoders where memory may be limited. For this purpose (amongst others) the look object may include a counter which indicates the number of graphical objects which are associated with that look object. Preferably, each time a graphical object is associated with the look object, the counter is incremented, and each time a graphical object is disassociated with the look object, the counter is decremented. If the counter is at zero, then it may be assumed that the look object can be safely deleted.

[0020] In the method of the invention, comprises defining a graphical object in a graphical user interface, comprising providing a look object which controls the appearance of the graphical object (for example, by defining properties and/or methods which control the appearance of the graphical object), and providing a widget object which controls operation of the graphical object (for example, by defining properties and/or methods which control the operation of the graphical object). Any of the features mentioned above may be provided in combination with this aspect.

[0021] Any of the methods described above preferably further comprise displaying the graphical object, for example on a screen such as a computer screen or a television screen.

[0022] Any of the methods described above may be carried out by a receiver/decoder, such as a digital or analogue television receiver/decoder.

[0023] The term "receiver/decoder" used herein may connote a receiver for receiving either encoded or non-encoded signals, for example, television and/or radio signals, which may be broadcast or transmitted by some other means. The term may also connote a decoder for decoding received signals. Embodiments of such receiver/decoders may include a decoder integral with the receiver for decoding the received signals, for example, in a "set-top box", such a decoder functioning in combination with a physically separate receiver, or such a decoder including additional functions, such as a web browser, a video recorder, or a television.

[0024] In an apparatus aspect of the invention there is provided apparatus for controlling the appearance of an object oriented widget in a graphical user interface, as defined in claim 6.

[0025] The apparatus may include a suitably programmed processor for defining the look object and for associating the look object with the graphical object, and memory for storing the look object and the graphical object. The look object may be defined by object-oriented program code. The look object may be defined by instantiating a look object class. The look object may contain a pointer to another look object class.

[0026] The apparatus may be adapted to modify the appearance of the graphical object, by redefining or modifying the look object, or by associating a different look object with the graphical object. The look object may include an update counter (such as a location in memory) whose value is updated when the look object is re-defined or modified.

[0027] The look object may include a validation mask (for example, stored in memory) which indicates methods that can be called by the look object.

[0028] The apparatus may be apparatus for controlling the appearance of a plurality of graphical objects in a graphical user interface, and may be adapted to associate the look object with a plurality of graphical objects. The look object may include a counter (such as a location in memory) which indicates the number of graphical objects which are associated with that look object.

[0029] The apparatus may further comprise means, such as a screen (for example a computer screen or a television screen) for displaying the graphical object.

[0030] A widget set for creating objects as described above is provided, the widget set comprising a plurality of widget classes and one or more look object classes. Most typically, the widget set comprises a plurality of look object classes including a base class and a class derived from the base class.

[0031] In order to amend the appearance of the object, the look object class can be changed. This does not change the function of the object since function is controlled by the widget class. Moreover, it is possible for one instance of the look object class to be used by many instances of the widget class, thereby minimising the amount of memory used.

[0032] The look object class can be contained in a library linked into an application at run time. A user can therefore select a preferred look for the object by selecting which one of a range of libraries should be linked. Because the look object class is changed independently of the other items, re-coding is simplified to the minimum necessary to implement the new look.

[0033] Alternatively, the look object class can be contained in a library linked into an application at compile time. This allows an application developer to have full control of the appearance of the object.

[0034] The look object class may export drawing methods that can be invoked to draw part of a component on a GUI display. The widget class typically contains code which invokes drawing methods of the look object class. The look object class may also export properties which provide data relating to elements of a component.

[0035] The look object class may be a default class which provides a default look for widgets in a GUI display. Alternatively, the look object class may be a class derived from a default class, the derived class overriding one or more methods and/or properties of the default class. By this arrangement, a user or a developer can make changes to just a limited number of elements within the look of a GUI without having to re-work any parts which are to remain unchanged.

[0036] The look object class instance may be a property of the widget class instance. Typically, a pointer to an instance of the look object class is assigned to a property of the widget class instance. Such a pointer may be passed as an argument to a constructor of the widget class.

[0037] In a method according to the last-preceding paragraph, a pointer to the look object class is typically stored in instance memory of the widget class instance.

[0038] By controlling operation, it is not necessarily meant that the object is functional; whereas sliders and buttons and the like may be capable of performing actions, some graphical objects may simply be decorative, such as symbols or parts of composite objects. Thus the properties and/or methods which control operation of the object may do little more than determine the basic function of the object (for example to appear as a pointer), with the precise appearance being controlled by the look object.

[0039] It will be understood that the present invention has been described herein purely by way of example, and modifications of detail can be made within the scope of the invention.

[0040] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

[0041] Where features of the apparatus are described herein as "means for" a particular function, it is intended that those terms be interpreted broadly and are preferably not interpreted to be limited to any particular embodiment of the invention described herein. Features of the apparatus are, in preferred embodiments provided by a suitably programmed computer or computers, and thus features of the apparatus are preferably provided by the relevant features of a computer or product comprising a computer program. For example, features of the apparatus may be provided by a processor, or other part of a computer, for example a memory or data store.

[0042] Features of one aspect may be applied to any other aspect; method features may be applied to apparatus aspects and vice versa.

[0043] Preferred features of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which:

Figure 1a shows an overview of a typical digital television system;

Figure 1b shows the general architecture of the interactive television system;

Figure 2a is a block diagram of a receiver/decoder;

Figure 2b shows the architecture of a receiver/decoder;

Figure 2c illustrates further the architecture of the receiver/decoder;

Figure 3 is a diagram of part of the hierarchy of widgets within a widget set;

Figure 4 is a simplified diagram of a widget appearing on a GUI display;

Figure 5 illustrates the location in memory of several widgets

Figure 6a illustrates a screen display of the web browser;

Figure 6b shows a remote control for navigating the web browser;

Figure 7 illustrates a further screen display of the web browser;

Figure 8 illustrates a further screen display of the web browser;

Figure 9 illustrates a further screen display of the web browser;

Figure 10 illustrates a further screen display of the web browser;

Figure 11 illustrates a further screen display of the web browser;

Figure 12 illustrates a further screen display of the web browser;

Figure 13 illustrates a further screen display of the web browser;

Figure 14 illustrates a further screen display of the web browser;

Figure 15 illustrates a further screen display of the web browser;

Figure 16 illustrates a further screen display of the web browser;

Figure 17 illustrates a further screen display of the web browser;

Figure 18 illustrates a further screen display of the web browser,

Figure 19 illustrates a further screen display of the web browser;

Figure 20 illustrates a further screen display of the web browser;

Figure 21 illustrates a further screen display of the web browser;

Figure 22 illustrates a further screen display of the web browser;

Figure 23 illustrates a further screen display of the web browser;

Figure 24 illustrates a further screen display of the web browser;

Figure 25 illustrates a further screen display of the web browser,

Figure 26 illustrates a further screen display of the web browser;

Figure 27 illustrates a further screen display of the web browser;

Figure 28 illustrates a further screen display of the web browser;

Figure 29 illustrates a further screen display of the web browser;

Figure 30 illustrates a further screen display of the web browser;

Figure 31 is an example of a graphical object formed by tiling;

Figure 32 is a further example of a graphical object formed by tiling;

Figure 33 is a further example of a graphical object formed by tiling;

Figure 34 is a further example of a graphical object formed by tiling;

Figure 35 is a further example of a graphical object formed by tiling;

Figure 36 is a further example of a graphical object formed by tiling;

Figure 37 is a further example of a graphical object formed by tiling;

Figure 38 is a further example of a graphical object formed by tiling;

Figure 39 illustrates the method of tiling graphical objects;

Figure 40 shows a typical image buffer;

Figure 41 shows the layout of a tiled graphical object.

Figure 42 schematically illustrates the operation of a virtual keyboard;

Figure 43 shows a typical mapping of characters to keys on a virtual keyboard;

Figure 44 shows examples of a virtual keyboard; and

Figure 45 shows typical dimensions of a virtual keyboard.

Overview of a digital television system

[0044] An overview of a digital television system 1 is shown in Figure 1a. The invention includes a mostly conventional digital television system 2 that uses the known MPEG-2 compression system to transmit compressed digital signals. In more detail, MPEG-2 compressor 3 in a broadcast centre receives a digital signal stream (typically a stream of video signals). The compressor 3 is connected to a multiplexer and scrambler 4 by linkage 5.

[0045] The multiplexer 4 receives a plurality of further input signals, assembles the transport stream and transmits compressed digital signals to a transmitter 6 of the broadcast centre via linkage 7, which can of course take a wide variety of forms including telecommunications links. The transmitter 6 transmits electromagnetic signals via uplink 8 towards a satellite transponder 9, where they are electronically processed and broadcast via notional downlink 10 to earth receiver 12, conventionally in the form of a dish owned or rented by the end user. Other transport channels for transmission of the data are of course possible, such as terrestrial broadcast, cable transmission, combined satellite/cable links, telephone networks etc.

[0046] The signals received by receiver 12 are transmitted to an integrated receiver/decoder 13 owned or rented by the end user and connected to the end user's television set 14. The receiver/decoder 13 decodes the compressed MPEG-2 signal into a television signal for the television set 14. Although a separate receiver/decoder is shown in Figure 1a, the receiver/decoder may also be part of an integrated digital television. As used herein, the term "receiver/decoder" includes a separate receiver/decoder, such as a set-top box, and a television having a receiver/decoder integrated therewith.

[0047] In a multichannel system, the multiplexer 4 handles audio and video information received from a number of parallel sources and interacts with the transmitter 6 to broadcast the information along a corresponding number of channels. In addition to audiovisual information, messages or applications or any other sort of digital data may be introduced in some or all of these channels interlaced with the transmitted digital audio and video information.

[0048] A conditional access system 15 is connected to the multiplexer 4 and the receiver/decoder 13, and is located partly in the broadcast centre and partly in the receiver/decoder. It enables the end user to access digital television broadcasts from one or more broadcast suppliers. A smartcard, capable of deciphering messages relating to commercial offers (that is, one or several television programmes sold by the broadcast supplier), can be inserted into the receiver/decoder 13. Using the receiver/decoder 13 and smartcard, the end user may purchase commercial offers in either a subscription mode or a pay-per-view mode. As used herein, the term "smartcard" includes, but not exclusively so, any chip-based card device, or object of similar function and performance, possessing, for example, microprocessor and/or memory storage. Included in this term are devices having alternative physical forms to a card, for example key-shaped devices such as are often used in TV decoder systems.

[0049] As mentioned above, programmes transmitted by the system are scrambled at the multiplexer 4, the conditions and encryption keys applied to a given transmission being determined by the access control system 15. Transmission of scrambled data in this way is well known in the field of pay TV systems. Typically, scrambled data is transmitted together with a control word for descrambling of the data, the control word itself being encrypted by a so-called exploitation key and transmitted in encrypted form.

[0050] The scrambled data and encrypted control word are then received by the decoder 13 having access to an equivalent to the exploitation key stored on a smart card inserted in the decoder to decrypt the encrypted control word and thereafter descramble the transmitted data. A paid-up subscriber will receive, for example, in a broadcast monthly ECM (Entitlement Control Message) the exploitation key necessary to decrypt the encrypted control word so as to permit viewing of the transmission.

Interactive system

[0051] An interactive system 16, also connected to the multiplexer 4 and the receiver/decoder 13 and again located partly in the broadcast centre and partly in the receiver/decoder, enables the end user to interact with various applications via a modemmed back channel 17. The modemmed back channel may also be used for communications used in the conditional access system 15.

[0052] Figure 1b shows the general architecture of the interactive television system 16 of the digital television system 1.

[0053] For example, the interactive system 16 allows an end user to buy items from on-screen catalogues, consult local news and weather maps on demand and play games through their television set.

[0054] The interactive system 16 comprises in overview four main elements:-

• an authoring tool 4004 at the broadcast centre or elsewhere for enabling a broadcast supplier to create, develop, debug and test applications;
• an application and data server 4006, at the broadcast centre, connected to the authoring tool 4004 for enabling a broadcast supplier to prepare, authenticate and format applications and data for delivery to the multiplexer and scrambler 4 for insertion into the MPEG-2 transport stream (typically the private section thereof) to be broadcast to the end user;
• a virtual machine including a run time engine (RTE) 4008, which is an executable code installed in the receiver/decoder 13 owned or rented by the end user for enabling an end user to receive, authenticate, decompress, and load applications into the working memory of the decoder 13 for execution. The engine 4008 also runs resident, general-purpose applications. The engine 4008 is independent of the hardware and operating system; and
• a modemmed back channel 17 between the receiver/decoder 13 and the application and data server 4006 to enable signals instructing the server 4006 to insert data and applications into the MPEG-2 transport stream at the request of the end user.

[0055] The interactive television system operates using "applications" which control the functions of the receiver/decoder and various devices contained therein. Applications are represented in the engine 4008 as "resource files". A "module" is a set of resource files and data. A "memory volume" of the receiver/decoder is a storage space for modules. Modules may be downloaded into the receiver/decoder 13 from the MPEG-2 transport stream.

Receiver/decoder

[0056] Referring to Figure 2a, the various elements of receiver/decoder 13 will now be described in terms of functional blocks.

[0057] The receiver/decoder 13, which may be, for example, a digital set-top box (DSTB), comprises a central processor 220 including associated memory elements and adapted to receive input data from a serial interface 221, a parallel interface 222, a modem 223 (connected to the modem back channel 17 of Fig. 1a), and switch contacts 224 on the front panel of the decoder.

[0058] The receiver/decoder is additionally adapted to receive inputs from an infra-red remote control 225 via a control unit 226 and also possesses two smartcard readers 227, 228 adapted to read bank and subscription smartcards 242, 240 respectively. The subscription smartcard reader 228 engages with an inserted subscription card 240 and with a conditional access unit 229 to supply the necessary control word to a demultiplexer/descrambler 230 to enable the encrypted broadcast signal to be descrambled. The decoder also includes a conventional tuner 231 and demodulator 232 to receive and demodulate the satellite transmission before being filtered and demultiplexed by the unit 230.

[0059] Processing of data within the receiver/decoder is generally handled by the central processor 220. Figure 2b illustrates the software architecture of the central processor 220 of the receiver/decoder. With reference to Figure 2b, the software architecture comprises a Run-Time-Engine 4008, a Device Manager 4068 and a plurality of Devices 4062 and Device Drivers 4066 for running one or more applications 4056.

[0060] As used in this description, an application is preferably a piece of computer code for controlling high level functions of preferably the receiver/decoder 13. For example, when the end user positions the focus of remote control 225 on a button object seen on the screen of the television set 14 and presses a validation key, the instruction sequence associated with the button is run.

[0061] An interactive application proposes menus and executes commands at the request of the end user and provides data related to the purpose of the application. Applications may be either resident applications, that is, stored in the ROM (or FLASH or other non-volatile memory) of the receiver/decoder 13, or broadcast and downloaded into the RAM or FLASH memory of the receiver/decoder 13.

[0062] Applications are stored in memory locations in the receiver/decoder 13 and represented as resource files. The resource files comprise graphic object description unit files, variables block unit files, instruction sequence files, application files and data files, as described in more detail in the above-mentioned patent specifications.

[0063] The receiver/decoder contains memory divided into a RAM volume, a FLASH volume and a ROM volume, but this physical organization is distinct from the logical organization. The memory may further be divided into memory volumes associated with the various interfaces. From one point of view, the memory can be regarded as part of the hardware; from another point of view, the memory can be regarded as supporting or containing the whole of the system shown apart from the hardware.

Software architecture

[0064] The central processor 220 can be regarded as centred on a run time engine 4008 forming part of a virtual machine 4007. This is coupled to applications on one side (the "high level" side), and, on the other side (the "low level" side), via various intermediate logical units discussed below, to the receiver/decoder hardware 4061, comprising the various ports as discussed above (that is, for example, the serial interface 221, the parallel interface 222, modem 223, and control unit 226).

[0065] With specific reference to Figure 2b, various applications 4057 are coupled to the virtual machine 4007; some of the more commonly used applications may be more or less permanently resident in the system, as indicated at 4057, while others will be downloaded into the system, eg from the MPEG data stream or from other ports as required.

[0066] The virtual machine 4007 includes, in addition to the run time engine 4008, some resident library functions 4006 which include a toolbox 4058. The library contains miscellaneous functions in C language used by the engine 4008. These include data manipulation such as compression, expansion or comparison of data structures, line drawing, etc. The library 4006 also includes information about firmware in the receiver/decoder 13, such as hardware and software version numbers and available RAM space, and a function used when downloading a new device 4062. Functions can be downloaded into the library, being stored in FLASH or RAM memory.

[0067] The run time engine 4008 is coupled to a device manager 4068 which is coupled to a set of devices 4062 which are coupled to device drivers 4060 which are in turn coupled to the ports or interfaces. In broad terms, a device driver can be regarded as defining a logical interface, so that two different device drivers may be coupled to a common physical port. A device will normally be coupled to more than one device driver; if a device is coupled to a single device driver, the device will normally be designed to incorporate the full functionality required for communication, so that the need for a separate device driver is obviated. Certain devices may communicate among themselves.

[0068] Each function of the receiver/decoder 13 is represented as a device 4062 in the software architecture of the receiver/decoder 13. Devices can be either local or remote. Local devices 4064 include smartcards, SCART connector signals, modems, serial and parallel interfaces, a MPEG video and audio player and an MPEG section and table extractor. Remote devices 4066, executed in a remote location, differ from local devices in that a port and procedure must be defined by the system authority or designer, rather than by a device and device driver provided and designed by the receiver/decoder manufacturer.

[0069] The run time engine 4008 runs under the control of a microprocessor and a common application programming interface (API). They are installed in every receiver/decoder 13 so that all receiver/decoders 13 are identical from the application point of view.

[0070] The engine 4008 runs applications 4056 on the receiver/decoder 13. It executes interactive applications 4056 and receives events from outside the receiver/decoder 13, displays graphics and text, calls devices for services and uses functions of the library 4006 connected to the engine 4008 for specific computation.

[0071] The run time engine 4008 is an executable code installed in each receiver/decoder 13, and includes an interpreter for interpreting and running applications. The engine 4008 is adaptable to any operating system, including a single task operating system (such as MS-DOS). The engine 4008 is based on process sequencer units (which take various events such as a key press, to carry out various actions), and contains its own scheduler to manage event queues from the different hardware interfaces. It also handles the display of graphics and text. A process sequencer unit comprises a set of action-groups. Each event causes the process sequencer unit to move from its current action-group to another action-group in dependence on the character of the event, and to execute the actions of the new action-group.

[0072] The engine 4008 comprises a code loader to load and download applications 4056 into the receiver/decoder memory. Only the necessary code is loaded into the RAM or FLASH memory; in order to ensure optimal use. The downloaded data is verified by an authentication mechanism to prevent any modification of an application 4056 or the execution of any unauthorized application. The engine 4008 further comprises a decompressor. As the application code (a form of intermediate code) is compressed for space saving and fast downloading from the MPEG stream or via a built-in receiver/decoder mode, the code must be decompressed before loading it into the RAM. The engine 4008 also comprises an interpreter to interpret the application code to update various variable values and determine status changes, and an error checker.

Architecture of receiver/decoder

[0073] The receiver/decoder contains five software layers, organized so that the software can be implemented in any receiver/decoder and with any operating system. Referring to Figure 2c, the various software layers are Application Layer 250, Application Programming Interface (API) layer 252, Virtual Machine Layer 254, Device Layer 256 and System Software/Hardware Layer 258.

[0074] The Application Layer 250 encompasses applications that are either resident in or downloaded to the receiver/decoder. They may be interactive applications used by customers, written in, for example, Java, HTML, MHEG-5 or other languages, or they may be applications used by the receiver/decoder to run such applications. This layer is based on a set of open Application Programming Interfaces (APIs) provided by the Virtual Machine layer. This system allows applications to be downloaded to flash or RAM memory in the receiver/decoder on-the-fly or on demand. The application code can be transmitted in compressed or uncompressed format using protocols such as Data Storage Media Command and Control (DSMCC), Network File Server (NFS) or other protocols.

[0075] Interactive applications are applications that the user interacts with, for example, to obtain products and services, such as electronic program guides, telebanking applications and games.

[0076] Various security features are provided for these downloaded applications and data, as follows:

• Nothing can be downloaded to the receiver/decoder without first having been authenticated for the intended network, which prevents any unregistered software from being run in the receiver/decoder. This means that any software running in the receiver/decoder is recognized and has been fully tested.
• A Security Manager limits access of applications to various memory zones, thus assuring data integrity.
• The system can interface with any conditional access system that makes use of secure processors (for example, smart cards inserted in the receiver/decoder).

[0077] The following resident applications are used to manage interactive applications:

• Boot. The Boot application 260 is the first application launched when the receiver/decoder is powered on. The Boot application starts the different "Managers" in the Virtual Machine, the first being the Application Manager 262.
• Application Manager. The Application Manager 262 manages the interactive applications that are run in the receiver/decoder, that is, it starts, stops, suspends, resumes, handles events and deals with communication between applications. It allows multiple applications to run at once, and thus is involved in the allocation of resources among them. This application is completely transparent to the user.
• SetUp. The purpose of the SetUp application 264 is to configure the receiver/decoder, primarily the first time it is used. It performs actions such as scanning for TV channels, setting the date and time, establishing user preferences, and so on. However, the SetUp application can be used at any time by the user to change the receiver/decoder configuration.
• Zapping. The Zapping application 268 is used to change channels using the Program-up, Program-down and numeric keys. When another form of zapping is used, for example, through a banner (pilot) application, the Zapping application is stopped.
• Callback. The Callback application is used to extract the values ofvarious parameters stored in the receiver/decoder memory and return these values to the commercial operator via modemmed back channel 17, or by other means.

[0078] The API layer 252 provides high-level utilities for interactive application development. It includes several packages that make up this high-level API. The packages provide all the functionality necessary to run interactive applications. The packages are accessible by the applications.

[0079] In a preferred embodiment the API is adapted to run applications written in the Java programming language. Furthermore, it can interpret HTML and other formats, such as MHEG-5. Besides these interpreters, it also includes other packages and service modules that are detachable and extensible as requirements dictate.

[0080] The Virtual Machine layer 254 is composed of language interpreters and various modules and systems. It consists of everything necessary to receive and execute interactive applications in the receiver/decoder, including the following:

• Language Interpreters. Different interpreters can be installed to conform to the type of applications to be read. These include Java, HTML, MHEG-5 and others.
• Service Information (SI) Engine. The SI Engine loads and monitors common Digital Video Broadcasting (DVB) or Program System Information Protocol (PSIP) tables and puts them into a cache. It allows access to these tables by applications which need the data contained in them.
• Scheduler. This module allows for pre-emptive, multithreaded scheduling with each thread having its own event queue.
• Memory Manager. This module manages the access to memory. It also automatically compresses data in memory when necessary and performs automatic garbage collection.
• Event Manager. This module allows events to be triggered according to priority. It manages timer and event grabbing and allows applications to send events to each other.
• Dynamic Linker. This module allows the resolution of addresses arising from native Java functions, loads native methods from a Java class downloaded into RAM and resolves calls from downloaded native codes towards ROM.
• Downloader. This module uses automatic data loading from a remote DSMCC carousel or through the NFS protocol, with downloaded files accessed in the same way as resident ones. Memory clear-up, compression and authentication are also provided.
• Class Manager. This module loads classes and resolves any class referencing problems.
• File System. This module is compact and optimized to manage a hierarchical file system with multiple ROM, flash, RAM and DSMCC volumes. Flash integrity is guaranteed against any incidents.
• Security Manager. This module authenticates applications and controls the access of applications to sensitive memory and other zones of the set-top box.
• Graphics System. This system is object-orientated and optimized. It includes graphic window and object management as well as a vectorial font engine with multi-language support.

[0081] Furthermore, the DAVIC resource notification model is supported so that client resources are efficiently managed.

[0082] The Device Interface layer 256 includes a Device Manager and devices. Devices are software modules which consist of the logical resources necessary for management of external events and physical interfaces. The Device Layer manages communication channels between drivers and applications and provides enhanced error exception checking. Some examples of managed devices are: card readers, modems, network, PCMCIA (Personal Computer Memory Card International Association), LED display and so on. Programmers do not have to deal with this layer directly, since the API layer controls the devices from above.

[0083] The System Software/Hardware layer 258 is provided by the manufacturer of the receiver/decoder. Because of the modularity of the system and because services supplied by the OS (such as event scheduling and memory management) are part of the Virtual Machine, the higher layers are not tied to a particular real-time operating system (RTOS) or to a particular processor.

Widget sets

[0084] In a preferred embodiment, a widget set is provided for use in applications to run in a graphical user interface (GUI). One particular application of such a widget set is to provide widgets in a GUI display of a receiver/decoder for digital television. Each widget is implemented as an object-oriented module such that, for each widget, there is a corresponding widget class. Thus, any widget may be built up from simpler component widgets by inheriting or aggregating classes of other widgets.

[0085] Figure 3 is a simplified diagram of the hierarchy of widgets within a widget set. In this embodiment, the widget set contains a set of primitive widget classes 410 including, amongst others, widow and dialogue box frames, a slider control, a push button, a check box, a text field, and a text editing box. At a next level of complexity, there are classes 420 which combine several primitive widget classes or modify the behaviour of a primitive widget. For example, a widget such as a list box may create editable list items from a text editing box class and allow a user to scroll through the list using a scroll bar derived from a slider control class. At yet a higher level of complexity, the widget set contains aggregate widgets 430 such as a file selection dialogue box which contains push buttons, scrollable lists, text fields and text editing boxes, all of which are defined in other classes of the widget set.

[0086] Each of the widget classes implements methods and event handlers to control operation of the widget. The widget classes may also contain methods for drawing some parts of the widget. However, in order to provide a particular appearance or "look" for the widget, the widget classes invoke drawing methods of a look object class with which the widget class is associated. This will be described in further detail below.

Look class public methods and API

[0087] In order that the look object classes and widget classes can interact, it is necessary for the look object classes to have a consistent set of public methods that are guaranteed to be available for use by the widget class. In particular, the look object class must provide a standard API, which contains methods that the widget class can invoke in order to draw itself on a GUI display.

[0088] The API used by widgets is defined in a base class, from which all looks are derived. The API comprises the following elements:

1. General display methods

2. Particular display methods

3. Control of the creation and destructions of instances

4. Control of borders

5. Control of modifications

[0089] General display methods are those which are available to all widgets while particular display methods are particular to certain types of widget.

[0090] Looks are constructed using a hierarchical architecture. A new look class is created by inheriting the attributes, methods and default values of the class from which it is derived, and then adding new attributes, methods and default values, or overriding some or all of those inherited.

[0091] A look class is organised as a table containing pointers to public methods. A look class which is derived from another look class may therefore redefine a method by changing the relevant pointer so that it points to another method. Typically, a look class only implements some of the available public methods.

[0092] In one implementation, public methods, known as dummy methods, are provided, which do nothing other than return the call. If a method not implemented by the look class is called by the widget, a dummy method is called. This is done in order to ensure error free functioning of method calls even when the method is in fact not implemented. A disadvantage of calling dummy methods is that time may be wasted in calling a method which does nothing.

[0093] In another implementation, look classes are provided with validation masks. A validation mask defines which methods can be called by the look class, so that methods which are not implemented are not called. A widget can access the validation mask of a look class to optimise the drawing of the widget. In this case, the widget is aware of methods which are not implemented, so the widget will avoid generating calls to such methods. In this way, it is possible to prevent time from being wasted in calling dummy methods.

[0094] A look class may be derived from two or more other classes (multi-heritage). This can enable a look class to be created that is an union of two or more other looks. As mentioned above, when a look class is created, it adopts the attributes, methods and default values of the look class from which it is derived. In order to implement multi-heritage, the look also contains one or more pointers to the additional classes from which it derives attributes, methods and default values. The look can then access those attributes, methods and default values, without having to copy or create them itself.

[0095] In another embodiment, when a look class is created, it adopts the attributes, methods and default values of all of the look classes from which it is derived.

[0096] The principle of multi-heritage is also useful in situations where non-standard widgets are designed, which may require the look to implement non-standard methods. A pointer in the look can point to a second look class which contains the non-standard methods that are required to display the widget.

[0097] It is important to ensure that the various look classes from which a look is derived do not conflict with each other. This can be done by ensuring that the additional look classes only contain methods which are not in the main look class from which the look is derived, or by giving an order of precedence to the various classes.

[0098] An example of the public methods of a look object class is set forth below.

Creating and displaying a widget

[0099] When an application requires a widget to appear on the display of a GUI, the first task it must perform is to construct an instance of the widget class. During creation of the widget instance, a look class instance becomes associated with the widget class instance. The particular look is chosen as follows:

1. If a look class instance is passed by the application to the constructor, then use it.

2. Otherwise, use the default look specified for the class of widget being created, if there is one.

3. Otherwise, use the default look specified for the widget context, if there is one.

4. Otherwise, use the default look for the widget set.

[0100] Once the widget class has been instantiated, the application can invoke an appropriate one of its public methods to display it.

[0101] The widget class also preferably provides a public method that can be called with a pointer to a look class instance, and that look class instance then becomes associated with the widget class instance. This causes the appearance of the widget to change in accordance with the newly associated look class instance. It should be understood that "association" is, in reality, nothing more than setting the value of a field within the widget class instance. To associate the widget with a different look class can, in the simplest of embodiments, be done simply by making an assignment to the field. (However, see the comments below relating to memory management and the method MhwWgtXxxSetLook.) Moreover, many widget class instances may be associated with one look class instance. This is illustrated diagrammatically in Figure 5.

[0102] When a widget class method is called to draw the widget on a GUI display, it builds the image of the widget in the following order:

1. The background of the widget (for example, a background colour or an image).

2. Background overlay (for example, a logo)

3. Foreground of the widget

4. Foreground overlay (for example, a logo)

5. The widget border.

6. Highlighting

7. Input focus.

[0103] For a given widget, certain parts may be absent. The presence or absence of a part of the widget depends on the following criteria.

1. Hard coding. Some of the parts are not defined for certain classes of widget.

2. Optional parts. For example, the focus, the relief and the highlight may be inhibited at will by means of a public attribute of the widget.

3. Definition of the look. A look can omit one or more of the parts.

[0104] In a typical example, the following steps are carried out.

[0105] Firstly the background of the widget is drawn by the widget class method itself, for example, by painting a background colour, a background pattern or an image. The background overlay is then drawn by invoking the public method of the associated look instance MhwWgtLookDrawBackground specifying appropriate arguments for the height, width and position of the widget on the display. The appearance of the background is thus modified by the look, for example, by overlaying a logo.

[0106] The widget class method must then build up the foreground of the widget; that is to say, it creates the visual objects that actually are manipulated by a user or display information when the widget is in use. For example, the widget might implement a check box, in which case it invokes the look class method MhwWgtLookDrawCheckSymbol. The look may then modify the foreground, for example by overlaying a logo.

[0107] The border region of the widget is then drawn, as will be described below.

[0108] If the widget class determines that one of the objects within the widget has input focus, it invokes the look class method MhwWgtLookDrawFocus to indicate this in the displayed widget. Similarly, if part of the widget is to be highlighted, the widget class invokes the look class method MhwWgtLookDrawHighlight.

Widget border management

[0109] One specific example of the way in which the look controls the appearance of the widget on a GUI display is in the management of borders. The appearance of a widget with borders in its most general form on a GUI display is shown in Figure 4. The widget 500 occupies a rectangular area in the display of a GUI. The area occupied by the widget includes two regions: an inner operative region 510 surrounded by a border region.

[0110] The border region typically does not contribute to the function of the widget (although it may, in some cases, by used by a user to move and/or re-size the widget). Therefore, there is considerable scope for variation of the appearance of the border region in accordance with a user's wishes. For example, the colour, width, background pattern can all be selected to appeal to a user or to provide a consistent appearance. Therefore, responsibility for drawing the border is given to the look class.

[0111] The look maintains four dimensions to specify the width of the border. These specify the distance from the left, right, top and bottom of the operative region 510 to the edge of the widget. These dimensions are indicated respectively at L, R, T, and B in Figure 4. Values for these dimensions are specified in the default look. An application may define a class derived from the default look class in which the values are overridden to create a look that creates a widget with a border of non-standard width. An application (for example, a look manager) can also change the values at run time by invoking the look methods MhwWgtLookAttsSetBorderwidthBottom, MhwWgtLookAttsSetBorderWidthLeft, MhwWgtLookAttsSetBorderwidthRight, or MhwWgtLookAttaSetBorderWidthTop.

[0112] Within the look class there is code that controls the detailed layout of a border according to values passed to the look class by the widget class.

Widget colour management

[0113] A look also includes a definition of colours, so that any widget instance which is associated with a particular look instance will use the colours defined in that look instance. In one embodiment, a look defines the following colours:

• black
• dark gray
• middle gray
• light gray
• very light gray
• white
• transparent
• highlight colour

[0114] The colour definitions in the look are used when drawing a widget. For example, if a black line is to be drawn when displaying a widget, the colour which has been defined as "black" will be used. For example, if the look is to have a red hue, then "black" may be defined to be dark red, and "white" may be defined to be light pink, with various shades of red being defined in between. In this example, a drawing operation which would normally draw a black line will instead draw a dark red line, and so on.

[0115] In addition, the look defines a colour map which sets the actual colour values which are to be used when displaying any particular colour on the display of a GUI.

Creating a modified widget

[0116] Suppose that the default look method MhwWgtLookDrawCheckSymbol draws a rectangular box which is either empty or which contains a small tick symbol depending on its state, and that this defines the look of a normal check box in a GUI. Now suppose that another widget is required in which either a tick or a cross is displayed. The appearance is entirely controlled by the look class, so only the look class need be altered. Moreover, a new look class to implement this behaviour can be derived from the existing look class, and provide only one method MhwWgtLookDrawCheckSymbol to override the method of the same name in the base look class. Moreover, when the method MhwWgtLookDrawCheckSymbol is invoked with the argument aState set to true, the method MhwWgtLookDrawCheckSymbol of the base class can be called to draw a tick. New code need be written only to handle the case where a cross is to be drawn. Thus, a new widget can be created with a minimum of programming effort.

[0117] It should be understood that this procedure does not alter the appearance of the original check box widget; this widget uses the base look class which has not been amended. In order to effect a change to the appearance of the original check box widgets in an application, the method MhwWgtLookDrawCheckSymbol in the base look class must be amended. All check box widgets derived from that class will then change their appearance following the next occasion (at compile time, or run time, as the case may be) upon which the look class is linked with the application.

[0118] The widget class will, in principle, co-operate to create a widget with any class having an appropriate set of public methods and properties as a look class. However, there is advantage in deriving all look classes from as small as possible a number of common base classes, and ideally just one base class. Those familiar with object-oriented programming will understand that this minimises the use of memory and other resources by the look classes. A derived class has a pointer to its base class so that it can access method code and static data of the base class without duplication of such code or data in memory.

Version Control

[0119] It may be that some widget instances have a very long life. For example, the root window of a window manager, a taskbar widget in a workstation display, and so forth. In such cases, there is a strong possibility that the look classes might be updated during the life of the widget. The widget class must be caused to re-draw itself when this happens.

[0120] One a way to achieve this is to give each look class an update counter which is exported as a public property or is accessible though a public method. When a widget class is instantiated, the widget class instance queries the update counter of the associated look, and stores the value of the update counter in memory local to the widget class instance. If the instance of the look class is subsequently updated, the widget class instance can detect this change by comparing the value that is stored in its local memory with the value of the update counter in the look class instance. If the look class instance has been updated, the widget can then re-draw itself using the methods of the look class.

Construction and Destruction of Look Class Instances

[0121] In general, there will be fewer instances of each look class than of each widget class. In some cases, there may be just one instance of a look base class referred to by all widget class instances in an application. There may also be instances of derived look classes referred to by some of the widget class instances of an application. However, a widget class cannot assume that there will always be a look class instance in existence at the time that the widget class is being instantiated; the widget instance might be the first to require association with a particular look class.

[0122] Therefore, it is proposed that during instantiation of each widget class, the widget class constructor invokes the associated look class constructor MhwWgtLookNew. If no instance of the look class exists, then a new instance is created. A value of 1 is then stored in a reference counter held in the local memory of the look class instance. If an instance of the look class already exists, the look class constructor returns a pointer to it, and increments the reference counter.

[0123] During destruction of each widget class instance, the destructor of the widget class invokes the destructor MhwWgtLookDelete for the associated look class instance. The destructor MhwWgtLookDelete decrements the reference counter. If the counter remains greater than zero, the destructor simply returns. However, if the destructor reaches zero, then no widget class instances (other that the one undergoing destruction) are associated with that look class instance, in which case the look class destructor proceeds to remove the look class instance from memory.

[0124] The widget class method MhwWgtXxxSetLook can be called to change the look with which a particular widget class instance is associated. Within this method, a call is first made to the destructor of the outgoing look class instance, and a call is then made to the reference function of the new look class to obtain a pointer to a class instance. This ensures that the reference counters of the look classes are properly updated.

[0125] There must also provision for a new instance of a look class to be created even if an instance already exists. This allows an application to have more than one instance of any given look class, and to set different attributes in the different instances. For example, there may be two instances of the same look class identical in all respects other than one has all attributes remaining in accordance with their defaults, and the other having different values assigned to one or more of its attributes (border width, colour, and so forth).

Look Managers

[0126] As will be understood, the system of look classes and instances allows very detailed control over the overall look of an application. For instance, just one attribute of any look class can be changed to effect a minor change to the look of an application. Accordingly, a look manager application may be provided to enable a user to alter these attributes as required. Such an application typically includes a GUI display including widgets embodying the invention in order that the user can immediately see the effect of changing the attributes of the look upon the appearance of the widget.

Web browser

[0127] The internet navigator interface will now be described with reference to the accompanying drawings.

[0128] Figure 6a shows a screenshot of the main screen navigator display of an Internet browser. The main screen shows a vertical chain 1100 which includes the main menu which includes various buttons as a linked list. The buttons are linked by link elements of the chain. The buttons shown in the chain 1100 of Figure 6a include the RELOAD/STOP button 1110, the PREVIOUS button 1120, NEXT button 1130, HISTORY button 1140, BOOKMARK button 1150, SETTINGS button 1160 and the QUIT button 1170.

[0129] The main menu chain 1100 is arranged to be superimposed on the hyper-text markup language (HTML) document to be displayed on the screen 1101. In Figure 6a, no HTML document is displayed and the screen 1101 is blank apart from the main menu chain 1100.

[0130] The web browser includes several preferences which can be set by the user. The browser includes a facility for setting several user profiles.

[0131] The user has a controller with which he can navigate between objects on the screen 1101, highlight objects and select objects. In the present example, the controller used is a television remote control 1180. The number keys 1181 are used to enter data; the cursor keypad 1182 is used to navigate around the screen. The cursor keypad 1182 includes an UP key 1183, a DOWN key 1184, a LEFT key 1185 and a RIGHT key 1187. The cursor keypad 1182 also incudes a SELECT key 1186 which is used for selecting objects on the screen.

[0132] The UP key 1183 and the DOWN key 1184 are used to more a focus,in this example a highlight up and down the chain 1100 to selectively highlight the buttons 1110, 1120, 1130, 1140, 1150, 1160 and 1170. When a button is highlighted, it can be selected using the select key 1186.

[0133] When an HTML page is displayed, any button of the remote control calls the chain 1100 (toolbar). The chain 1100 can also be turned on and off by the user. In one settings option the chain 1100 automatically is hidden when a new HTML page is displayed, the user calling up the chain 1100 when he wants to move to another HTML page.

[0134] Figure 7 shows the screen of Figure 6a having an HTML document open. Information about the open document is given in a text box 1112 linked in the chain to the RELOAD/STOP button 1110. It will be seen that the chain links 1114 between the buttons indicate visually to the user that he can move between the buttons in the direction of the links.

[0135] Figure 6a shows the RELOAD/STOP button highlighted (the highlighted RELOAD/STOP icon is white on a dark background rather than dark on a white background as in Figure 7 where it is not highlighted). The HTML document can be reloaded by pressing the select key 1186 when the RELOAD/STOP button is highlighted.

[0136] The user moves the highlight down the chain 1100 using the DOWN key 1184. In Figure 7, the PREVIOUS button 1120 is now highlighted. Figure 8 shows how, when the highlight is on the PREVIOUS button 1120 a "tooltip" comprising a text box 1122 appears on the screen. In the present example, the tooltip appears as soon as the relevant icon is highlighted. The preferences could be set so that the tooltip appears after a delay when the button is highlighted. The text box 1122 includes the word "previous" to indicate the function of the PREVIOUS button 1120. By activating the PREVIOUS button, by pressing the SELECT key 1186, the browser moves to the previous page viewed.

[0137] In Figure 9, the highlighting is moved down to the NEXT button 1130 and, after a short time, a tooltip comprising a text box 1132 including the word "next" appears to assist the user.
In Figure 10, the HISTORY button 1140 is highlighted and its associated tooltip 1142 appears with the word "history". The HISTORY button 1140 has more than one function and so, activating the button by pressing the SELECT key 1186 on the control keypad causes a sub-chain 1144 to appear giving further options relating to the history function. The sub-chain 1144 is shown in Figure 11. The sub-chain 1144 includes additional buttons including a VIEW button 1146 and an ADD button 1148. The user moves along the sub-chain 1144 using the RIGHT and LEFT keys 1187, 1185. In the screen display of Figure 11, the VIEW button is highlighted and a tooltip 1147 appears to tell the user that the button highlighted is VIEW. It will be noted that the tooltips attached to the main chain 1100 appeared on the right hand side of the chain 1100; the tooltips for the sub-chain appear above the sub-chain.

[0138] The size of the box for the tooltip is matched to the length of the word or words to be displayed. Where different language preferences can be set, the size of the box for the tooltip is preferably matched to the length of the word in the language selected.

[0139] Figure 12 shows the display obtained when the VIEW button is selected. A VIEW HISTORY window 1141 appears on the screen having a heading 1143 (here the French language option has been selected for the heading) and showing details 1145 of previous pages viewed by the user. The user may scroll up and down the text and highlight one of the details 1145 using the SELECT key 1186. The LEFT and RIGHT keys are used to highlight the OK or CANCEL keys 1149, 1149'.

[0140] Figure 13 shows the ADD button 1148 highlighted and its associated tooltip. The ADD button 1148 is used to add the presently displayed page to the history list 1145.

[0141] Figure 14 shows the BOOKMARK button 1150 highlighted and its associated tooltip 1151. In Figure 15, the BOOKMARK button 1150 has been selected and the bookmark sub-chain 1152 is shown including the tooltip 1151, the VIEW, ADD, DELETE and EDIT buttons, 1153, 1154, 1155, 1156. In Figure 15, the VIEW button 1153 is highlighted and its tooltip shown. The VIEW button 1153 is selected and the VIEW window 1157 is shown (see Figure 16). (It will be seen that, for clarity, the bookmark sub-chain 1152 is not shown when the view window 1157 is on the screen.) The VIEW window 1157 includes a heading, and a scrollable text box listing bookmarks. As for the VIEW HISTORY window, the window also includes OK and CANCEL keys. The cursor keypad 1182 is used to navigate about the window and to select a bookmark, if desired.

[0142] In Figure 17, the ADD button 1154 is highlighted and its tooltip is displayed. If the ADD button is selected, the ADD window is displayed (see Figure 18). The ADD window 1158 includes two boxes for text entry to enter the URL of the bookmark and its title. Data is entered into the window using the number keys 1181 (for example using the on-screen keyboard described herein). The window also includes OK and CANCEL keys as described above. The user navigates between the text entry boxes and the OK and CANCEL keys using the cursors 1182.

[0143] Figure 19 shows the DELETE button 1155 highlighted and its tooltip. By selecting the DELETE button 1155, bookmarks may be deleted.

[0144] Figure 20 shows the EDIT button 1156 highlighted and its tooltip. By selecting the EDIT button 1156, bookmarks may be edited.

[0145] Figure 21 shows an alternate form of the bookmark sub-chain 1152 in which the bookmark tooltip 1151 is not shown. This can save space on the screen, in particular if the sub-chain is long. The appearance of the tooltips is an option which can be selected by the user.

[0146] Figure 22 shows the SETTINGS button 1160 highlighted, and its tooltip 1161. When SETTINGS is selected, the authentication window 1165 is displayed (see Figure 22) prompting the user to identify himself and to give the user password before the settings can be altered. The authentication window 1165 includes two text entry boxes for the entry of the usemame and password using the number keys 1181 and OK and CANCEL buttons. Once the correct username and password have been entered into the authentication window 1165 and the OK button selected, the settings sub-chain 1162 is displayed, see Figure 24.

[0147] The settings sub-chain 1162 includes the MODEM button 1163 and the BROWSER button 1164. Figure 24 shows the MODEM button 1163 highlighted and its associated tooltip. By selecting the MODEM button 1163, the settings of the modem may be changed. Figure 25 shows the BROWSER button 1164 highlighted and its associated tooltip. When the BROWSER button 1164 is selected, the browser window 1166 is displayed, see Figure 26. Again, the user navigates around the objects in the window using the cursor keys 1182. The objects in the browser window include a COLOUR drop-down list 1167. By highlighting the list head and selecting it using the cursor keys 1182, the items of the list appear and the user can move up and down the list and select a new browser colour using the cursors. Similarly, the text language of the browser can be changed using the drop-down list 1168. By moving the highlight to the tooltip select 1169 and pressing the select button 1186, the tooltips can be turned on and off. The window includes, as before, OK and CANCEL buttons.

[0148] Figure 27 shows the QUIT button 1170 highlighted and its associated tooltip 1171. If the QUIT button 1170 is selected, the quit sub-chain 1172 appears (Figure 28). In Figure 28, the CONFIRM button 1173 is highlighted and has its tooltip displayed. If the user wishes to quit the web browser, he selects the CONFIRM button 1173. If the user wants to cancel the quit selection, he selects the CANCEL button 1174 shown highlighted in Figure 29 with its tooltip.

[0149] Alternative designs of the main menu chain 1100 may be used, whereby the shape of the individual buttons and the texture can been changed preferably without changing the overall shape of the chains. The colour may also be changed. These changes can be made available as options in the settings menu, the shape and texture of the chain being changed as a whole to give a coherent design (skin) for the browser.

[0150] For example, the buttons might have square, circular, diamond or other shapes, with a texture preferably designed to give a three-dimensional appearance. The appearance of the links between the buttons may be designed to match the appearance of the buttons, or alternatively to complement it. The appearance of the links may also be chosen so as to give the appearance of structural solidity, to enhance the user's perception that the buttons are meaningfully interlinked.

[0151] The arc shape of the chain shown in Figures 6-30 is chosen by the developer, and is preferably not alterable by the user. Other configurations of the button chain and sub-chains are possible, such as a straight chain or a semi-circular chain. In other embodiments, the button order and configuration of the button chain and sub-chains may be modified by the user.

[0152] The receiver/decoder provides internet navigation and email-reading capabilities.

[0153] The graphical studio for modelling a navigator is now discussed.

[0154] The graphical studio for modelling a navigator is an ensemble or collection of elementary graphical objects. Each graphical object is the pictorial representation on a television screen of one of the functions of the navigator. Each function of the navigator can be represented by a graphical object, or by a sequence of images of a graphical object (an animated image), or a collection of graphical objects (for example, an image in the background of the screen or an image in the background of a dialog box to which other graphical objects can be attached). There are two internal formats for images: MPEG2 and PIXMAP-GRL.

[0155] The PNG format is used for elementary graphical objects representing the "navigation system" functionality: load, connect, previous document, next document, exit, etc.

[0156] To imprint a non-rectangular image on the graphical plane, it is necessary to use a clipping mask which defines the visible (significant) zones. This mask must be provided by the designer in the form of a bitmap: this mask is not calculated by the program owing to performance constraints.

[0157] The two stages for adding a clipping mask are first displaying an image and then, in the graphical plane, filling in a rectangle of the same dimension and position of the image with the transparency colour while applying the clipping mask to render visible the useful part of the image.

[0158] The PIXMAP-GRL image format is used for graphical objects representing the navigator resources or the user interface: vertical scrollbar, tables, simple choice, multiple choice, etc.

[0159] The PIXMAP type objects are of variable dimension (each graphical object or model is decomposed into simple elementary objects) and colourable (changing colour).

[0160] The PIXMAP-GRL image format may be obtained by converting any other graphical formats (such as BMP, JPEG, GIF, PNG, etc.) using well-known methods.

[0161] The decomposition of a graphical object into graphical elements is effected according to a matrix (e.g. 3x3, 4x4 or 1x4) which depends on the type of object being displayed.

[0162] The palette contains 256 colours. This palette is applied to graphical objects of type PIXMAP and PNG. In a palette, there are two parts. The first part consists of 26 colours which are reserved to facilitate the display and the design of the application. The second part consists of 230 non-modifiable colours which are available for use by applications.

[0163] The maximum size of the screen is 720 pixels wide by 576 high. To guarantee the visibility of the screen on every low-end television set, it is necessary to restrict the size to 592 pixels wide and 480 high. To exploit high-end television sets, the user will have the option to adjust the size of the screen. For an internet navigator, sites have in general designed their pages 600 pixels wide and 400 high.

[0164] The generic attributes of a graphical object are now discussed in detail.

[0165] A graphical object (according to what it represents) has a precise size. The exact size is defined by the designer and serves as a guide for the display.

[0166] Each graphical object is resizeable. According to the type of graphical object, it is possible to resize the width and/or height. The method of resizing of a PIXMAP-GRL graphical object follows the recommendations of the decomposition of a graphical object. The method of drawing variable size graphical objects is discussed further later on.

[0167] The image of the graphical object on the screen is represented by a multicoloured shape; the background image should have a range of colours if possible (fluid, the effect of modelling clay).

[0168] The image of the graphical object does not have to be drawn according to its position (coordinates), or according to the order of the following or preceding object on the screen: the notion of a floating position of the object. Each object is by definition independent of the other objects (except for a background image).

[0169] The text is printed by the program according to the chosen language. This implies that no image should contain text. The design of an object is left in the hands of the designer. The general look can follow a particular theme (e.g. Startrek, 007, the Simpsons).

[0170] The aspect of focus can be represented by several means: a rectangular focus on the graphical object; a focus highlighting (with another colour) the background of the graphical object, or a focus colouring in the shape of the graphical object.

[0171] The normal state (without focus, active, not depressed) is the basic one of the graphical object.

[0172] The inhibited state of a graphical object can be represented by several means: the shape of the object in grey (or vignetted); the overlaying of a distinctive prohibitive sign on the graphical object in question; setting the background of the object to monocolour, or making the object invisible.

[0173] The depressed state of a graphical object is the graphical representation of an object having the focus following a click on it but before the button is released. This representation can be an inverse display of the object or it can be the same as the focussed state.

[0174] With regard to the flip-flop (head to tail) display effect, an image or icon may comprise two visual aspects: one representing the text (the reverse, or 'tails' side of a Euro coin, for example), the other representing a symbol (the face, or 'heads' side). This visual effect is animated by a program running on a timer; a timer is started at the display of a first icon, and as soon as the timer reaches a predetermined value, the change of icon takes place: either a second icon is displayed, or a sequence of icons showing a progressive change is displayed.

[0175] The decomposition of a graphical object of PIXMAP-GRL type is now described, with reference to Figures 31 to 38. These figures show examples of the elementary graphical objects used in the matrix decomposition method (1201-1209, 1211-1219, etc.), and the corresponding graphical object formed when the elementary objects are combined in the appropriate fashion (1210, 1220, etc.). The figures have been enlarged approximately by a factor of four.

[0176] To be able to resize a graphical object (increase or decrease), each graphical object (a design created by the graphic artist) is split into the form of a matrix of graphical elements like the pieces of a puzzle. Each element is then referenced according to the four cardinal corners and the centre (north, south, east, west, centre, north-east, north-west, south-east, south-west, centre of the centre). The width and height of the matrix depends on the type of object.

[0177] Certain graphical elements (pieces of the puzzle) are printed only once (the corners). To make the object wider or taller, certain elements are printed in a repetitive fashion (n times the width or height of the element, respectively).

[0178] Graphical objects which are formed by, or form part of, the matrix decomposition (or tiling) method are now listed. These graphical objects are drawn in the HTML document area.

• Button with/without text in the active state (1210): 3x3 matrix (1201-1209); size of elements: 4 pixels wide and high; elements to resize the width: north-centre (1202), centre (1205), south-centre (1208); elements to resize the height: west-centre (1204), centre (1205), east-centre (1206).
• Button with/without text in the active, depressed state (1220): 3x3 matrix (1211-1219); size of elements: 4 pixels wide and high; elements to resize the width north centre (1212), centre (1215), south-centre (1218); elements to resize the height: west-centre (1214), centre (1215), east-centre (1216).
• Button with/without text in the inactive, greyed state (1230): 3x3 matrix (1221-1229); size of elements: 4 pixels wide and high; elements to resize the width: north-centre (1222), centre (1225), south-centre (1228); elements to resize the height: west-centre (1224), centre (1225), east-centre (1226).
• 'Check box', shown with/without focus, and crossed/uncrossed (Figure 34): 1x1 matrix; size of elements: 16 pixels wide and high; elements to resize the width: none; elements to resize the height: none.
• List of options, for single or multiple selection (1252, 1253, 1254): 3x3 matrix (1241-1249); size of elements: 4 pixels wide and high; elements to resize the width: north-centre (1242), centre (1245), south-centre (1248); elements to resize the height: west-centre (1244), centre (1245), east-centre (1246); can comprise an up (1250) and/or down indicator (1251); position: x,y origin + width and height of the up indicator.
• Up indicator (1250): 1x1 matrix; size of elements: 16 pixels wide and 8 pixels high; elements to resize the width: none; elements to resize the height: none; position: y origin, centred on the width
• Down indicator (1251): 1×1 matrix; size of elements: 16 pixels wide and 8 pixels high; elements to resize the width: none; elements to resize the height: none; position: y origin + height of up indicator + height of list, centred on the width.
• Table (for drawing forms) (1260): 3x3 matrix (1270); size of elements: 2 pixels wide and high; elements to resize the width: north-centre, centre, south-centre; elements to resize the height: west-centre, centre, east-centre; can comprise a cell.
• Cell (for drawing an entry in a form) (1280): 3x3 matrix (1290); size of elements: 2 pixels wide and high; elements to resize the width: north-centre, centre, south-centre; elements to resize the height: west-centre, centre, east-centre; can comprise text or an image; position: x,y origin + thickness of the table border.
• Text with frame (TextArea) (1300): 3x3 matrix (1310); size of elements: 2 pixels wide and high; elements to resize the width: north-centre, centre, south-centre; elements to resize the height: west-centre, centre, east-centre; can comprise text.
• Frame (1320): 3x3 matrix (325); size of elements: 4 pixels wide and high; elements to resize the width: north-centre, centre, south-centre; elements to resize the height: west-centre, centre, east-centre
• Vertical scrollbar (1330): 1×3 matrix; size of elements: 8 pixels wide and high; elements to resize the width: none; elements to resize the height: centre; attached to the frame (depending on the position of the frame object); comprises the indicator graphical object of the index relative to the height.
• Horizontal scrollbar (1340): 3x1 matrix; size of elements: 8 pixels wide and high; elements to resize the width: centre; elements to resize the height: none; attached to the frame (depending on the position of the frame object); comprises the indicator graphical object of the index relative to the width.
• Horizontal line: 1x1 matrix; size of elements: 4 pixels wide and high.
• Vertical line: 1x1 matrix; size of elements: 4 pixels wide and high.

[0179] A summary of all of the graphical objects in the web browser interface and their associated functions is now given.

[0180] What follows is a non-exhaustive list of the graphical objects which are necessary for the construction of a navigator model in the decoder. The table given here lists the objects element-by-element and the list of objects composed of several graphical elements.

Elementary graphical object	Functionality	Type	Comments
BTN_Connecter	Connect/disconnect the modem line	Clickable PNG image	Initiates the modem connection with the defined profile information
BTN_Déconnecter	Connect/disconnect the modem line	Clickable PNG image	Disconnects the modem
BTN_Information_Profil	Access to the authentication information for the connection profile	Clickable PNG image	Displays a dialog box for configuring the subscriber profile: login, password and telephone number
BTN_Infonnation_Serve ur	Rapid access to the proxy server information	Clickable PNG image	Displays a dialog box for configuring the parameters of the proxy servers
BTN_Configuration_nav igateur	Rapid access to the navigator options	Clickable PNG image	Displays a dialog box for configuring the navigator options
BTN_Accés_Email	Rapid access to the email application	Clickable PNG image	Starts the email client
BTN _Document_Précéd ent	Previous page	Clickable PNG image	Displays the immediately preceding HTML page
BTN_Document_Suivant	Next page	Clickable PNG image	Displays the immediately following HTML page
BTN_Stop_Chargement	Stop the current document loading	Clickable PNG image	Stops the current document from loading
BTN_Annuaire	Rapid access to bookmarks	Clickable PNG image	Displays a dialog box contaiiiing the bookmark list
BTN_Quitter	Leaves the application and returns to TV	Clickable PNG image	Leaves the application
BTN_Saisie_Adresse	Rapid access to the selection of a link	Clickable PNG image	Opens the dialog box from which one can access a site address (URL) or from which one selects an established URL
IMG_Logo_Navigateur	Logo	Clickable PNG image	Circular sequence of images to display the current loading activity
IMG_Logo_Opérateur	Logo	Clickable PNG image
IMG_Diode	Status or activity indicator	Non-clickable PNG image	Coloured diodes (LEDs): red, green, blue, black, yellow
BTN_Flèche_haut	Move up one row	Clickable and non-clickable PNG image	Clickable images indicating: depressed state, non-depressed state and inhibited state Non-clickable images indicating: inhibited and normal status
BTN_Flèche_bas	Move down one row	Clickable and non-clickable PNG image	Clickable images indicating: depressed state, non-depressed state and inhibited state Non-clickable images indicating: inhibited and normal status
BTN_Flèche_droite	Move cursor forward	Clickable and non-clickable PNG image	Clickable images indicating: depressed state, non-depressed state and inhibited state Non-clickable images indicating: inhibited and normal status
BTN_Fleche_gauche	Move cursor backward	Clickable and non-clickable PNG image	3 clickable images: depressed state, non-depressed state and inhibited state 2 non-clickable images: inhibited and normal status
BTN_Page_haut	Move cursor up several rows (half a page or previous page)	Clickable and non-clickable PNG image	3 clickable images: depressed state, non-depressed state and inhibited state 2 non-clickable images: inhibited and normal status
BTN_Page_bas	Move cursor down several rows (half a page or following page)	Clickable and non-clickable PNG image	3 clickable images: depressed state, non-depressed state and inhibited state 2 non-clickable images: inhibited and normal status
BTN_Frame_Suivante	Go to next frame	Clickable PNG image	3 clickable images: depressed state, non-depressed state and inhibited state. This image is visible if there is a frame following; otherwise the image is not displayed to avoid overloading the screen
BTN_Frame_Précédente	Go to previous frame	Clickable PNG image	3 clickable images: depressed state, non-depressed state and inhibited state. This image is visible if there is a frame following; otherwise the image is not displayed to avoid overloading the screen
BTN_Choix_Croix	Indicator of whether an option within a list is checked or not	Clickable and non-editable PNG image	Like a box for insertion of a cross. Multiple choice possible. Hence there are 2 images: checked and non-checked
BTN_Choix_Simple	Indicator of whether an option within a list is checked or not	Clickable and non-editable PNG image	Like a box for insertion of a cross. Only one choice from a list. Hence there are 2 images: checked and non-checked
BTN_Ok	Validates a question or information	Clickable and non-editable PNG image	Generic validation image (without text). To be used in a dialog box...
BTN_Annuler	Deletes a question or information	Clickable and non-editable PNG image	Generic deletion image (without text). To be used in a dialog box...
BTN_Oui	Positive answer to a question	Clickable and non-editable PNG image	Generic validation image (without text). To be used in a dialog box...
BTN_Non	Negative answer to a question	Clickable and non-editable PNG image	Generic negation image (without text). To be used in a dialog box...
IMG_Curseur_Nonnal_S ouris	Pointer / graphics cursor	Normal graphics cursor indicator image	Like an arrow with a hotspot
IMG_Curseur_Attente_S ouris	Pointer in busy mode	Busy indicator	Like an egg timer or chronometer
IMG_Curseur_Texte	Position of the graphics cursor in a text during access	Indicator
IMG_Statusline	Display of a text in one row of 4/5 of the size of the screen	Background image for displaying non-editable text	Image without text. The text will be displayed in truncated format. The text has no more than 40 characters
IMG_Indéfinie	Generic display of an image not yet loaded	Clickable and non-clickable image	Image representing an image in an HTML document which has not yet been loaded into the memory, or whose loading was interrupted
BDG_Login_Password	Generic dialog box for displaying or entering the login and the password for accessing a secure site	Screen background image with graphic border	Background image delimiting an area of informational text, login field or password field. This dialog box is required to access a secure site. The program masks the password
BDG_Information_Profil	Generic dialog box for displaying or entering the login, password and telephone number of a distance access server.	Screen background image with graphic border	Background image delimiting an area of informational text, login field, password field or telephone number field. This dialog box is required before dialling the access server. The program masks the password, and confirmation of the password will be requested.
BDG_Confinnation_Pas sword	For confirming the entry of a password.	Dialog box having a background image with graphic border	Background image delimiting an area of informational text and a password field. This dialog box is required when the user modifies or enters a new password. The program masks the password
IMG_Telecommande_fil igrane	Filigree (outline of the keys) of the remote control for advanced entry using the virtual keyboard	Outline	The outline of the remote control is overlaid on the image of the virtual keyboard to make the keys of the remote control correspond visually to the layout of keys of the virtual keyboard. Rapid access by visual memory and not by documentary memory. The outline of the remote control keys does not consist of any letters or symbols.
BKG_Clavier_virtuel	Virtual keyboard for advanced entry using a remote control	Background image of a keyboard	The virtual keyboard is represented on the screen like that of a PC but without displaying letters or figures on the keys. Putting letters on each key is handled by the program: this allows the definition of a generic international language keyboard (azerty, qwerty or others). The outline image of the remote control is overlaid on the keyboard and follows the focus: this achieves the aim of showing visually that pressing a remote control button corresponds to a key press on the keyboard without having to memorize the translation in advance. The ESCape key dismisses the virtual keyboard. Certain keys serve as function keys: "http://www", ".fr", ".com", ".org", etc., and others have certain functions: "Enter", "Backspace", "Del", etc.
BKG_Toolbar_Navigatio n	Displayed in the toolbar background	Background image
BKG_Toolbar_Systeme_ Configuration	Displayed in the toolbar background	Background image
BKG _Annuaire	Displayed in the background of the bookmark dialog box	Background image
BKG_Information_Profil	Displayed in the background of the subscriber profile configuration dialog box	Background image
BKG_Information_Serve ur	Displayed in the background of the proxy server configuration dialog box

[0181] The following table describes the different elementary graphical objects which form a graphic object which can have a variable size in the graphical representation. The juxtaposition of elementary objects to make a complex object is effected by the program (reconstituting the puzzle). These objects are of PIXMAP format.

Elementary graphical object	Functionality	Type	Comments
TBL_Vertical_Gauche	To represent the border of a variable size table	Image	To draw a border on a table of variable size. This object represents a vertical stretch of the left side of the border
TBL_Verticat_Droite	To represent the border of a table	Image	To draw a border on a table of variable size. This object represents a vertical stretch of the right side of the border
TBL_Horizontal_Haut	To represent the boider of a table	Image	To draw a border on a table of variable size. This object represents a horizontal stretch of the top side of the border
TBL_Horizontal_Bas	To represent the border of a table	Image	To draw a border on a table of variable size. This object represents a horizontal stretch of the bottom side of the border
TBL_Angle_Haut_Gauc he	To represent the corner of the border of a table	Image	To draw the top left corner of a table border.
TBL_Angle_Haut_Droit e	To represent the corner of the border of a table	Image	To draw the top right corner of a table border.
TBL_Angle_Bas_Gauch e	To represent the corner of the border of a table	Image	To draw the bottom left corner of a table border.
TBL_Angle_Bas_Droite	To represent the comer of the border of a table	Image	To draw the bottom right corner of a table border.
CEL_Vertical_Gauche	To represent the border of a cell	Image	To draw the border of a cell. This object represents a vertical stretch of the left side of the border. A cell is one compartment in a table... The thickness of a cell border should be smaller than that of the table
CEL_Vertical_Droite	To represent the border of a cell	Image	To draw the border of a cell. This object represents a vertical stretch of the right side of the border.
CEL_Horizontal_Haut	To represent the border of a cell	Image	To draw the border of a cell. This object represents a horizontal stretch of the top side of the border.
CEL_Horizontal_Bas	To represent the border of a cell	Image	To draw the border of a cell. This object represents a horizontal stretch of the bottom side of the border.
CEL_Image	To represent the border of a non-loaded image in a cell	Generic image	Generic image representing the placement of a non-loaded image in a cell
BDG_Vertical_Gauche	To represent the border of a dialog box	Generic image	To draw the border of a variable-size dialog box. This object represents a vertical stretch of the left side of the border.
BDG_Vertical_Droite	To represent the border of a dialog box	Generic image	To draw the border of a variable-size dialog box. This object represents a vertical stretch of the right side of the border.
BDG_Horizontal_Haut	To represent the border of a dialog box	Generic image	To draw the border of a variable-size dialog box. This object represents a horizontal stretch of the top side of the border.
BDG_Horizontal_Bas	To represent the border of a dialog box	Generic image	To draw the border of a variable-size dialog box. This object represents a horizontal stretch of the bottom side of the border.
BDG_Angle_Haut_Gauc he	To represent the border of a dialog box	Generic image	To draw the top left corner of the border of a variable size dialog box.
BDG_Angle_Haut_Droit e	To represent the border of a dialog box	Generic image	To draw the top right corner of the border of a variable size dialog box.
BDG_Angle_Bas_Gauch e	To represent the border of a dialog box	Generic image	To draw the bottom left corner of the border of a variable size dialog box.
BDG_Angle_Bas_Droite	To represent the border of a dialog box	Generic image	To draw the bottom right corner of the border of a variable size dialog box.
LST_Vertical_Gauche	To represent the border of a vertical list of selectable options	Image	To draw the border of a variable size vertical list. This object represents a vertical stretch of the left side of the border.
LST_Vertical_Droite	To represent the border of a vertical list of selectable options	Image	To draw the border of a variable size vertical list. This object represents a vertical stretch of the right side of the border.
LST_Bas_Gauche	To represent the border of a vertical list of selectable options	Image	To draw the border of a variable size vertical list. This object represents a horizontal stretch of the top side of the border.
LST_Bas_Droite	To represent the border of a vertical list of selectable options	Image	To draw the border of a variable size vertical list. This object represents a horizontal stretch of the bottom side of the border.
LST_Angle_Haut_Gauc he	To represent the corner of the border of a variable size vertical list of selectable options	Image	To draw the top left corner of the border of a variable size vertical list.
LST_Angle_Haut_Droite	To represent the corner of the border of a variable size vertical list of selectable options	Image	To draw the top right corner of the border of a variable size vertical list.
LST_Angle_Bas_Gauch e	To represent the corner of the border of a variable size vertical list of selectable options	Image	To draw the bottom left corner of the border of a variable size vertical list.
LST_Angle_Bas_Droite	To represent the corner of the border of a variable size vertical list of selectable options	Image	To draw the bottom right corner of the border of a variable size vertical list.
ASC_Haut	To represent a vertical scroll bar ('elevator')	Clickable and non-clickable image	To draw the top end of a vertical scroll bar ('elevator')
ASC_Bas	To represent a vertical scroll bar	Clickable and non-clickable image	To draw the bottom end of a vertical scroll bar
ASC_Cage	To represent a vertical scroll bar	Clickable and non-clickable image	To draw one step ('floor') of a vertical scroll bar
ASC_Ascenseur	To represent a vertical scroll bar	Clickable and non-clickable image	To indicate the position of the vertical scroll bar
SCR_Gauche	To represent a horizontal scroll bar	Clickable and non-clickable image	To draw the left end of a horizontal scroll bar of a window, text area, frame, etc.
SCR_Droite	To represent a horizontal scroll bar	Clickable and non-clickable image	To draw the right end of a horizontal scroll bar of a window, text area, frame, etc.
SCR_Cage	To represent a horizontal scroll bar	Clickable and non-clickable image	To draw one compartment (step) of a horizontal scroll bar of a window, text area, frame, etc.
SCR_Position	To represent a horizontal scroll bar	Clickable and non-clickable image	To indicate the position of the cursor in the horizontal scroll bar of a window, text area, frame, etc.
IMG_Texte_Gauche	To represent a line of text to display	Non-clickable image	This is the image at the left side of the non-editable displayed text. The chosen size must match that of the chosen character set
IMG_Texte_Droite	To represent a line of text to display	Non-clickable image	This is the image at the right side of the non-editable displayed text. The chosen size must match that of the chosen character set
IMG_Texte_Caractere	To represent a line of text to display	Non-clickable image	This is the background image on which a non-editable character is printed. The chosen size must match that of the chosen character set,
IMG_Edition_Gauche	To represent a line of text to edit	Editable and clickable image	This is the image at the left side of an editable or selectable text zone. The chosen size must match that of the chosen character set.
IMG_Edition_Droite	To represent a line of text to edit	Editable and clickable image	This is the image at the right side of an editable or selectable text zone. The chosen size must match that of the chosen character set.
IMG_Edition_Caractere	To represent a line of text to edit	Editable and clickable image	This is the background image on which a character of an editable or selectable text zone is printed. The chosen size must match that of the chosen character set.
IMG_Multi_Edition_Ga uche	To represent the editing of multi-line text	Editable and clickable image	This is the image at the left side of an editable or selectable text zone. The chosen size must match that of the chosen character set.
IMG_Multi_Edition_Dro ite	To represent the editing of multi-line text	Editable and clickable image	This is the image at the right side of an editable or selectable text zone. The chosen size must match that of the chosen character set.
IMG_Multi_Edition_Car actere	To represent the editing of multi-line text	Editable and clickable image	This is the background image on which a character of an editable or selectable text zone is printed. The chosen size must match that of the chosen character set.

Navigator Functions

[0182] 

Function	Description	Activated by	Graphical Objects	Comments
Connect/disc onnect	Initiate the modem connection with the defined profile / disconnect the modem	BTN _Connecter BTN_Déconnect er		• Start the modem connection if it is off-line, if the connection profile information is filled in, if a URL is clicked.
Configure -modify the authentificati on information of the connection profile	Displays a dialog box to configure the subscriber profile: login, password, telephone	BTIV_Informatio n_Profil	BDG_Informati on_Profil	• Enter, modify, validate, store in flash memory the login, password and telephone number of the access server
				• Cancel the access
Confirm the entry of a password	Request the password to be re-entered	After a password has been changed	BDG Confirma tion_Password	• Enter, validate, cancel
				• Each entered character is replaced by a masking character (asterisk) when printed
				• Compare the entry with the modified password
Print or enter the login and password to access a secure site	Request authentificati on from the remote site	Following an attempt to access a secure site	BDG_Login_Pa ssword	• Enter, validate, cancel, sending information to the site
				• Each character of the password is replaced by a masking character (asterisk) when printed
Managing a virtual keyboard	Virtual keyboard for advance entry with a remote control	When the focus is on an editable object	BKG_Clavier_ Virtuel IMG_Telecom mande_filigrane	The virtual keyboard is represented on the screen like that of a PC but without displaying letters or figures on the keys. Putting letters on each key is handled by the program: this allows the definition of a generic international language keyboard (azerty, qwerty or others). The outline image of the remote control is overlaid on the keyboard and follows the focus: this achieves the aim of showing visually that pressing a remote control button corresponds to a key press on the keyboard without having to memorize the translation in advance. The ESCape key dismisses the virtual keyboard. Certain keys serve as function keys: "http://www", ".fr", ".com", ".org", etc., and others have certain functions: "Enter", "Backspace", "Del", etc.

[0183] The Java API for the web browser is now described.

[0184] There follows the list of the JAVA packages which are used at the level of the navigator application in the decoder. This list is divided into two parts: the AWT (Abstract Window Toolkit) classes of the JDK 1.1 and the JAVA interface classes of the different services written in native C code.

Classes	Methods
java.awt.Choice	Add(String)
	GetItemCount()
	GetSelectedIndex()
	Remove(String)
	SetSelectedIndex(int)
java.awt.Component	AddKeyListener(KeyListener)
	AddFocusListener(FocusListener)
	AddMouseListener(MouseListener)
	Contains(int,int)
	enableEvents(long)
	getLocation()
	getSize()
	setBackground(Color)
	setBackground(ImageMask)
	setBackground(int)
	setLocation(int)
	setSize(int,int)
java.awt.Graphics	draw Image
	getSize
	setLocation
java.awt.Image	createImage(String)
	getHeight()
	getWidth()
java.awt.ImageMask extends java.awt.Image	setMask(bitmap)
java.awt.List	List(int)
	add(String)
	getItem(num)
	getItemCount()
	getSelectedItem()
	remove(String)
	replace()
	setMultipleMode(boolean)
java.awt.Panel	setLayout(layout)
java.awt.Point
java.awt.Toolkit	loadLut(String)
	getDefauItToolkit()
java.awt.TextField	addActionListener(ActionListener)
	setEchoChar(char)
	setSecretMode()
java.awt.Window	setModal(boolean)
java.awt.event.FocusEvent
java.awt.event.FocusListener(interface)	void focusGained(FocusEvent)
	void focusLost(FocusEvent)
java.awt.event.KeyEvent
java.awt.event.KeyListener(interface)	void keyPressed(KeyEvent)
	void keyReleased(KeyEvent)
	void keyTyped(KeyEvent)
java.awt.event.MouseEvent
java.awt.event.MouseListener(interface)	void mouseClicked(MouseEvent)
	void mouseEntered(MouseEvent)
	void mouseExited(MouseEvent)
	void mousePressed(MouseEvent)
	void mouseReleased(MouseEvent)

[0185] The navigator package, called the browser package, groups together different packages: the browser.drawer package, which offers services allowing an HTML document to be fetched, and navigation within the document browser; and the mediawebtv package, which allows the establishment of an internet connection with the users authentification.

[0186] The structure of the browser.drawer.MhwBookmark class is now described.
A bookmark list is associated with a user. There is no hierarchy within the bookmark list.

Constructor:

MhwBookmark(subscriberId): opens an existing bookmark list

Constructor:

MhwBookmark(subscriberId): creates a new bookmark list

deleteBookmark():

destroys a bookmark list

add (URL, name):

adds an entry

remove (itemNumber):

deletes an entry

modify (itemNumber, URL, name):

modifies an existing entry

getList ():

returns a list of the entries in the bookmark list (no hierarchy)

getItemCount ():

returns the number of entries in the bookmark list

isFull ():

boolean - list is full?

isEmpty ():

boolean - list is empty?

setHomePage

(itemNumber)

getHomePage ():

itemNumber

goToURL (sessionNumber):

loads the document corresponding to the selected entry

[0187] In the event of failure, an error message is returned by the methods add(), remove(), modify(), getList(), setHomePage() (or an event if the occurrence is asynchronous).

[0188] The browser.drawer.MhwHistory class permits the navigation from one document to another within a list of previously displayed documents. There is no hierarchy in the history list. The details of the class are now given.

Constructor:

MhwHistory (sessionNumber)

getList ():

returns the history list (no hierarchy)

getCurrent ():

gets the current URL

setCurrent(indexNumber):

change the current URL

getNext ():

gets the URL of the next entry

getPrevious ():

gets the URL of the previous entry

getItemCount ():

returns the number of entries in the history

addEventsRegister ():

subscribes to the error events of the history list removeEventsRegister ()

[0189] In the event of failure, an error message is returned by the methods getList(), getNext(), getPrevious(), setCurrent() (or an event if the occurrence is asynchronous).
The events are: addEventsRegister(sessionNumber): [subscribes to the history list error events]; and removeEventsRegister(sessionNumber) [unsubscribes].

[0190] The browser.drawer.MhwDocument class allows the loading and displaying of an HTML document in the decoder. The details of the class are now given.

Constructor:

MhwDocument (sessionNumber)

freeze ():

halts the display of the current document (loading of the document continues)

unfreeze ():

restarts the display of the current document

isPending ():

whether the document is currently loading

stop ():

halts the loading of the current document

reload ():

reloads the document

getDocumentInfo ():

returns the title and the URL of the document

addStatusRegister ():

subscribes to information on the state and end of loading

goToURL (url):

loads a web page

submit (login, password, URL):

submits authentication for loading a web page

getStatisticsDocument ():

returns the number of requests in progress and the URL of the document currently being loaded

[0191] The browser.mediawebtv.MhwConnection class groups together the user connection and authentification functionality. The details of the class are now given.

Constructor:

MhwConnection (subscriberId)

start ():

requests connection

stop ():

requests disconnection

cancel ():

cancels the connection

setAuthentificationType (type):

sets the mode of authentication to the CANAL+ mode (msd/password) or by login/password

getAttributes ():

returns the connection attributes

setAttributes (attributes):

modifies the connection attributes

setPassword (password):

modifies the password

getPassword (password):

gets the password

setAutoCheckPassword (bAutoCheck):

sets whether the password is to be verified automatically with the confirmation password

getAutoCheckPassword (bAutoCheck):

reads whether the password is to be verified automatically with the confirmation password

getIPClient (ipaddress, netmask):

reads the selected IP and netmask pair

setIPClient (ipaddress, netmask):

modifies the IP and netmask pair

getDNS (dns1, dns2):

reads the primary and secondary DNS addresses

setDNS (dns1, dns2):

modifies the primary and secondary DNS addresses

getURLConfigServer (url):

reads the address of the configuration server

setURLConfigServer (url):

modifies the address of the configuration server

getQueryCommand (queryCmd, typeOfQuery):

reads by type the request to be sent to the configuration server

setQueryCommand (queryCmd, typeOfQuery):

modifies the request by type

queryAcquisitions (tableAcquisitions, typeOfAcquisition, NumberOfAcquisitions):

reads the list of acquisitions

startAcquisition (acquisitionId):

starts an acquisition (data/video)

stopAcquisition (acquisitionId):

stops an acquisition (data/video)

addStatusRegister ():

subscription to be informed of the connection status

[0192] The events are: loss of connection; current connection; established connection; connection confirmation request; connection error; modern status: on/off; initialisation an progress; dialling in progress; error but modem is on; server status: invalid port, invalid URL; login error: unknown login; and invalid password.

removeStatusRegister ():

unsubscribes to the network connection status

isConnected subscriberId():

returns boolean giving the modem connected/disconnected status

isPending ():

returns boolean for modem currently establishing connection

getExtendedProviderUrl (providerUrl):

reads the provider currently subscribed to

setExtendedProviderUrl (providerUrl):

modifies the provider currently subscribed to

[0193] The browser.mediawebtv.MhwConfigurarion class manages the profile of each user and his or her preferences. The details of the class are now given.

Constructor:

MhwConfiguration()

readProfile(subscriberId):

read the profile

writeProfile(subscriberId, profile):

write the profile

readDefaultProfile():

read the default profile

writeDefaultProfile(profile):

modify the default profile

getUserCount():

number of users

newUser(profile):

identifying for a new user

getLastConnect():

the last connected user

[0194] The maximum number of profiles is currently fixed at 5, but this does not represent a strict limit; higher numbers of profiles may be stored if need be.
In the case of failure, an error message is returned by the WriteProfile() and writeDefaultProfile() methods (or an event if the occurrence is asynchronous)

[0195] The browser.mediawebtv.MhwMultiSession class allows a navigator session to be selected. A session is an instance of the navigator which was automatically initiated by another instance. When the navigator starts, a session is created following the establishment of an authenticated connection. The details of the class are now given.

Constructor: MhwMultiSession

getCurrentSessionNumber()

setCurrentSessionNumber(int number)

getPreviousSession()

addSession(): returns the number of the session created

removeSession(int numSession)

[0196] The navigator model for the decoder is now described in more detail, with reference to Figures 6a and 7-30.

[0197] The model presented here is a simple example of a navigator, and gives a general idea of the principal functionality. It gives total freedom at the level of graphical representation. The only important features are the zones or screens within which functions of the same type are grouped and the general user interface.

[0198] The navigator employs all of the available graphics (MPEG, PIXMAP) of the graphical studio. The screens of this model are organised in tree form and each one groups together a collection of essential functions. Each function or option in a screen is accessed by moving a focus with the aid of arrow buttons (on the remote control) or by using a keypad with a cursor/pointer. The selection of an action is achieved by a controller click or by a predefined button (e.g. "OK").

[0199] In the absence of a physical keyboard, to enter text with the remote control, it is necessary to provide a virtual keyboard. This is achieved by moving the focus with a possibility of tapping quickly, by mapping the buttons of the remote control onto the virtual keyboard; in other words the image of the buttons on the remote control is visible (in traced form) in outline, or slightly opaque, on the picture of the virtual keyboard. The virtual keyboard is discussed in more depth later in this document.

[0200] Figure 30 shows the top-level chain of navigator function buttons (1410), with a portion of a web page visible beneath (1411).

[0201] The main navigator screen is now described, with specific reference to Figure 30.

[0202] The navigator functions are grouped in several layers. The main screen displays a vertical bar (main menu) (1410) which is composed of a series of buttons: Reload/Stop (1401), previous page (1402), next page (1403), history of recently visited sites, bookmarks, connect/disconnect, configuration, exit navigator (1408).

[0203] The navigator GUI (main screen) (1410) is displayed when a function key is pressed (either on the remote control or on the keyboard). When the GUI is visible on the TV screen, the HTML document (1411) (which the GUI covers over) continues to be loaded into memory, but the refresh of the document is suspended so as not to affect the display performance of the GUI. The HTML document is redisplayed when the navigator GUI is dismissed. This restriction will be lifted if the performances are eventually satisfactory, thereby allowing the simultaneous display of the HTML document and the GUI.

[0204] The GUI is dismissed from the TV screen by pressing a function key (on the remote control or the keyboard), or by clicking outside the GUI button zones. The display of the HTML document currently being loaded or stored in the cache memory is then started or recommenced.

[0205] A button is effectively a rectangular or square zone (for example, 32x32 pixels). When the graphics cursor enters a zone, that zone (window) receives the focus (cf. the EnterNotify(WindowId) function).

[0206] If the button graphic is a tyre, for example, it has to be detected whether the actual position of the graphics cursor effectively covers the pixels of the tyre. To this end, it is necessary to find the value of the pixel at the hotspot of the mouse pointer in the clipping mask of the button (by calculation of the relative position, getpixel() in the clipping mask, then testing the pixel value). This detection method allows the test to be improved for whether or not a click was effected before starting the function of the button.

[0207] When the mouse pointer leaves the button's rectangular or square zone, the zone loses the focus (cf. LeaveNotify(WindowId)).

[0208] The descriptive button summaries are now described in more detail.

[0209] When the mouse pointer or the rectangular focus coincides with a button representing a function, a short phrase (tooltip) is displayed either horizontally or vertically, describing the function of that button. When the button is selected, either by a mouse click or by a function key, a list of buttons appears containing sub-menu options. The system of short descriptive phrases (tooltips) is also used for the sub-menu buttons.

[0210] Navigation of the menu options is achieved with the arrow keys either on the remote control or on the keyboard. The last button on the main screen to have had the focus is remembered for the next time the main screen is displayed.

[0211] The virtual keyboard is now discussed in more detail, with reference to Figures 42-45.

[0212] Figure 42 shows schematically how the currently visible virtual keyboard (1501) maps onto the underlying 'grid' of virtual keyboards (1501, 1506).
Figure 43 shows a typical mapping of characters to keys on a virtual keyboard.

[0213] Figure 44 shows the images used for the virtual keyboard, with the first (1545) and second (1546) number block having the focus respectively (also showing two different types of remote control 1542 and 1543).
Figure 45 shows a typical virtual keyboard layout with typical dimensions superimposed.

[0214] Firstly, the virtual keyboard is conceived as an tool which is independent of the application in which it is used. This, it can be used within the "WebBrowser" application and equally within the "Mail" application. Moreover, its 'look' is completely independent of the 'look' of the application concerned.

[0215] The virtual keyboard is displayed from the moment that the user, not possessing a physical keyboard or a remote control with keyboard, selects an editable area of the screen. The focus is positioned at the end of the text in the editable area. Pressing "OK" (on the remote control or virtual keyboard) or "Cancel" (on the virtual keyboard) dismisses it.

[0216] The virtual keyboard which is visible on the screen (1501) is composed of three blocks of ten keys (representing three number blocks of the remote control) side by side (1502, 1503, 1504). The user can pass the focus (1505) from one block to another using the arrow keys on the remote control. After a block is selected, pressing a button on the number block of the remote control enters the corresponding character printed on the virtual keyboard.

[0217] The user can also use the up and down arrow keys. This brings the same virtual keyboard on the screen but with different characters on the keys (1506). Thus, flipping between a set of 5 virtual keyboards, one can display all of the characters on the keyboard of a western computer. There is also the possibility of adding other keyboards as the need arises.

[0218] With reference to Figure 44, to allow an immediate association to be made between the number block of the remote control and the focus on the virtual keyboard, a superimposed image of the remote control indicates the focus (1542, 1543). Thus the user can easily visualise that only one part of the keyboard has the focus, and that the rest of the characters can be reached by moving the focus with the arrow keys. The keyboard is designed with the latter points in mind.

[0219] The virtual keyboard solution takes up little screen height, and allows for easy extension of the number of characters available. By default, it is the virtual keyboard with the miniature alphabet which is displayed.

[0220] Certain buttons have important special functions: -

• "OK" on the remote control, for validing the current choice (if the field only has one line, the ¶ character (1521) also validates, or may alternatively be chosen to have no effect at all; otherwise, it corresponds only to a carriage return).
• "Cancel" (1522) on the virtual keyboard, to exit the tool without validating (the modifications made after opening the keyboard will be lost).
• "Back Space" (1523) on the virtual keyboard, which erases the last character entered.
• The up, down, left and right arrow keys, to move within the editing area.
• "Tab" (1520) on the virtual keyboard, which inserts a configurable number of spaces in one go (four by default).

[0221] The keyboard is always in 'insert' mode.
An example of a keyboard is given in Figure 44, and is discussed further below.

[0222] With the 5 keyboards (5x3) shown in Figure 43, and the two fonts installed for the WebBrowser application (Arialweb and Courier), all of the characters of a traditional keyboard can be covered. The dimensions of the keyboard on screen are 272 pixels wide by 184 pixels high.

[0223] The virtual keyboard and the functional connections with regard to its use in the various applications are developed within the "canalplus.virtualkbd" package.

[0224] The classes comprised within the package include "MhwVirtualKbd" (the virtual keyboard graphical description and behavioural class), "MhwVkTextField" (the class derived from 'java.awt.TextField' which allows a virtual keyboard defined within the global application sharing the TextField to control events) and "MhwTextArea" (a class inherited from the `java.awt.TextArea' which allows a virtual keyboard defined within the global application using the TextArea class to control events).

[0225] The MhwVirtualKbd class is now described in more detail.

[0226] The constructor of the "MhwVirtualKbd" class is defined as `private'. Thus only one unique virtual keyboard can be constructed, when the main application which may need to use it is started (in the absence of a physical keyboard, for example). The aim is therefore to present a keyboard configured especially for the current application, and which appears when the user enters a text field (single- or multi-line).

[0227] When the keyboard is created, the four main (static) variables which can be configured will have been set: -

• parent: container, 'parent' of the virtual keyboard, which must itself exist at the time the keyboard is created. It is set using the "setParent" method which returns a 'NullPointerException' if the 'parent' passed in the argument is 'null'.
• descriptive file: ASCII file which describes the keyboard, both in terms of the graphics behind the images, which concerns the various 'keyboards' obtained when the virtual keyboard is used, and the labels printed on the keys. The characters are specified by their unicode code. The name of the descriptive file can be set using the "setScreensFile" method.
• number of screens: number of 'number blocks' initialised and used by the virtual keyboard. This number, set using the "setScreensNumber", corresponds to the number of keyboards, the characteristics of which are read in the descriptive file detailed above.
• initial coordinates: these are the coordinates of the top-left corner of the background image of the keyboard in the parent container (described above). This is set using the "setCoordInit" method.

[0228] Once the keyboard is created, it can be decided whether or not to use it by using the "getInstance" method, which finds the keyboard of the current application, if it exists (if the virtual keyboard of the application does not yet exist, and if the application uses it, the "getInstance" method creates one, using for it the variables [the four previously described] which one would have set).

[0229] Event management is now described.

[0230] According to the preceding descriptions, the virtual keyboard functions, once displayed, solely by interpreting the events sent to it by: the number block, the "OK" button, and the four arrow direction keys on the remote control. These buttons will have specific rôles for the keyboard in use.

[0231] The "OK" button has an important rôle, because it allows the user to do two things: 'return' to the text field to enter information, and then display and start the operation of the virtual keyboard; and 'leave' the text field, saving the changes

Arrow keys

[0232] The 'right' and 'left' arrows allow the image of the remote control (indicating the number block which has the 'focus') to be moved on the three number blocks which are represented on the virtual keyboard. The keys of the number block on the remote control are thus 'bound', depending on the 'keyboard' having the focus, to the display of various characters.

[0233] In the most common case, 'tapping' on of these buttons when the virtual keyboard is active causes the automatic insertion of the character shown on that key, in the current text field at the position indicated by the cursor.

[0234] Of the characters, six can be considered as 'special' characters, and do not directly cause the character displayed on the key to be displayed in the text field:
BackSpace: '<' (1523): when the button on the remote control corresponding to this character is pressed, the character immediately to the left of the cursor position in the current text field is erased.
Tab: '>>' (1520): when the button on the remote control corresponding to this character is pressed, a configurable number of spaces (''), 4 by default, is inserted at the current cursor position.
Enter: '¶' (1521): when the button on the remote control corresponding to this character is pressed, a 'line feed' is inserted at the cursor position. In fact, if the current text field is an instance of the 'MhwVkTextField' class, i.e. one which only has one editable line, tapping this button will either have no effect or cause validation of the field. If, on the contrary, this text field is an instance of the 'MhwVkTextArea' class, it consists of several editable lines and this character causes a 'line feed' (if the cursor is positioned on the last editable line, tapping this button will have no effect).
Cancel: `¢' (1522): when the button on the remote control corresponding to this character is pressed, all of the modifications made to the current text field subsequent to the opening of the virtual keyboard are undone. In other words, its content is returned to the value it had before the modifications were made, and the virtual keyboard is 'exited'.
Left arrow: when the button on the remote control corresponding to this character is pressed, the cursor in the current text field is moved one place to the left. If the cursor is already in the 'zero' position (no further movement to the left is possible), this button has no effect. Right arrow: when the button on the remote control corresponding to this character is pressed, the cursor in the current text field is moved one place to the right. If the cursor is already positioned after the last character in the text field (and cannot move any further right), this button has no effect.
Up arrow: when the button on the remote control corresponding to this character is pressed, the cursor in the current text field is moved one place upwards. If the cursor is already in the first line of the text field (or if the current text field only has one line: MhwVkTextField), this button has no effect.
Down arrow: when the button on the remote control corresponding to this character is pressed, the cursor in the current text field is moved one place downwards. If the cursor is already in the last line of the text field (or if the current text field only has one line: MhwVkTextField), this button has no effect.

[0235] The "findLocation" method determines the placement of the virtual keyboard on the screen, seeking to minimise the "cropped" surface.

[0236] The MhwVkTextField class is simply a specialisation of the "TextField" class in the "java.awt" package. It additionally manages a boolean value which specifies the use (or not) of the virtual keyboard.
The constructors are exactly the same as those of the "TextField" class in the "java.awt" package, with a simple additional argument: a boolean specifying the use of the virtual keyboard.
If the boolean is "true", a 'base' instance of the "TextField" class is created, and a virtual keyboard listener, available within the current application, is also added at the same time, using the "addKeyListener" method. If not, a 'normal' TextField is created.
When the TextField has the focus, if the user presses 'OK' and the boolean specifies the use of the virtual keyboard, the virtual keyboard is displayed and gains the focus. It manages all of the events and is able to fill the text field. If the user presses 'OK' again, its text is validated, and the keyboard returns the focus. If the use of the virtual keyboard is not envisaged (boolean=false), the "TextField" has the same 'behaviour' as a standard TextField in "java.awt".

[0237] The MhwVkTextArea class is simply a specialisation of the "TextArea" class in the "java.awt" package. It additionally manages a boolean value which specifies the use (or not) of the virtual keyboard.

[0238] The constructors are exactly the same as those of the "TextArea" class in the "java.awt" package, with a simple additional argument: a boolean specifying the use of the virtual keyboard.
If the boolean is "true", a 'base' instance of the "TextArea" class is created, and a virtual keyboard listener, available within the current application, is also added at the same time, using the "addKeyListener" method. If not, a 'normal' TextArea is created.
When the TextArea has the focus, if the user presses 'OK' and the boolean specifies the use of the virtual keyboard, the virtual keyboard is displayed and gains the focus. It manages all of the events and is able to fill the text field. If the user presses 'OK' again, its text is validated, and the keyboard returns the focus. If the use of the virtual keyboard is not envisaged (boolean=false), the "TextArea" has the same 'behaviour' as a standard TextArea in "java.awt".

[0239] The following section describes further the implementation of features described above, and in particular the reconstruction of graphical objects (for example text fields, buttons, sliders, lists, checkboxes, choices etc.) from a set of graphical elements.

[0240] Figure 39 shows a button, for example, which is made from 9 elements: the four corners (NW 2100, NE 2101, SW 2102, SE 2103), the four sides (N 2104, E 2105, W 2106, S 2107) and the centre (C 2108).

[0241] Typically, but not necessarily, each of these 9 elements is square (4x4 pixels, 8x8 pixels, 16x 16 pixels). The blocks ofN, E, W, S and C elements are tiled within the area required (defined by the size of the component together with the border defined by the look). This area does not have to be a multiple of the size of the element. Currently, the tiling goes from left to right or top to bottom, so any incompletely drawn elements appear at the bottom and right hand sides. It could be envisaged to add "centered" and "right" justified tiling rules if this was felt to be useful. In general, the NW, NE, SW and SE elements are the same size as the border and so tiling is not necessary. If, however, they are smaller than required, the tiling is performed automatically.

[0242] A brief description follows of how this is implemented. The work is divided into three areas: the mechanism built into the native WGT module allowing the creation and assignment of different looks to different WGT widgets; the development of the native "LookPixmap" module, in which the functions for painting the different graphical features of components are included; and the development of the mhw.awt Java package for interfacing with the native code.

[0243] These three areas of development are described in the following sections.

[0244] The WGT module look mechanism will now be described, with references to Figures 40 and 41.

[0245] The aim of this section is to describe how the WGT module has been modified so as to be able to control the 'look' of the various graphic objects managed. New looks can be defined in new classes which can be added as and when necessary, leaving the WGT module untouched. A standard WGT look (LookWgt) is provided, instantiated and attributed to widgets by default so that applications not wishing to use this facility do not need to use it.

[0246] The following features are required: a number of different looks can be defined for each object type; a different look can be given to each object independently; and by default, the look defined by the current WGT is applied to objects.

[0247] Two different techniques for drawing the look of an object must be possible: bitmap and vectorial.

[0248] In the bitmap technique, the object is drawn by combining a number of predefined bitmap elements to create a single bitmap which is then drawn. To create objects of variable size, elements can be repeated, along the sides for example, in order to build an object of the required size.

[0249] Neither the size nor the precise arrangement of each of these elements is defined. The idea is to leave this as free as possible so that the creation of new looks is not overly restricted by WGT. The look class must define the bitmap elements and the rules for fitting them together as a function of the object size required.

[0250] The LookPixmap (native) and the PixmapLook (Java) classes described later use this method exclusively. There is nothing to stop developers creating their own look, derived or not from LookPixmap, which uses vectorial methods.

[0251] In the vectorial technique, the object is drawn using a series of basic draw operations such as DrawRectancle(), DrawArc(). The look class must define the rules for drawing the object as a function of the object size required.

[0252] It is perfectly possible to envisage a look class combining both Bitmap and Vectorial techniques. For example, the bitmap approach could be used for the basic form of a button, while the vectorial approach could provide the highlighting.

[0253] The WGT Module Look Mechanism are now discussed in more detail.

[0254] The following mechanisms have been incorporated:

• Division of the current paint method for each object into seven functions, certain of which are contained in the look class attributed to the object: DrawBackground(); MhwWgtLookDrawBackground(); DrawForeground(); MhwWgtLookDrawForeground(); MhwWgtLookDrawRelief(); MhwWgtLookDrawFocus(); MhwWgtLookHighlight()
• Creation of an abstract class MhwWgtLook.
• Creation of a class MhwWgtLookWgt derived from MhwWgtLook, and instantiated when WGT is initialized.
• Addition of a g_TheDefaultLook global variable used to set the look that will be attributed to each object when it is created if a specific look is not attributed MhwWgtXXXAttsSetLook.
• Addition of a public method MhwWgtSetDefaultLook(context) for changing the default look for objects.
• Addition to the object classes of two public methods, MhwWgtSetXXXAttrLook(*object, *look) and MhwWgtGetXXXAttsLook(*object).

[0255] These aspects are presented in the following sections, beginning with the methods for painting.

[0256] Each paint function now calls the following methods when it is called: DrawBackground(); MhwWgtLookDrawBackground(); DrawForeground(); MhwWgtLookDrawForeground(); MhwWgtLookDrawRelief(); MhwWgtLookDrawFocus(); and MhwWgtLookHighlight().

[0257] The two methods DrawBackground() and DrawForeground() are part of WGT and are called regardless of the look. The others are, in fact, pointers to the corresponding functions in the Look class associated with the widget in question. In this way, the look class implements the paint functions for these parts.

Background

This allows the look to draw behind the entire widget.

Foreground

This can be used to draw an image of other graphic over the central part of the widget (excluding the border).

Relief

This is called if the widget's relief flag is set and is used to draw a border or relief for the widget.

Focus

This is called if the widget has the focus. It can be used to indicate this graphically.

Highlight

This is called if the widget is highlighted. It can be used to indicate this graphically.

The abstract class MhwWgtLook is defined and contains the following:

[0258] WgtCoreLookClassMethod; WgtCoreLookClassField; WgtCoreLookClass; WgtCoreLookPart; and WgtCoreLookObject.

[0259] These are described below.

FIELDS:
MhwWgtLookClass	*extends;
Int32	classId;
String	ClassName;
Card16	mask;
Card8	borderwidthTop;
Card8	borderwidthBottom:
Card8	borderwidthLeft;
Card8	borderwidthRight;
MhwWgtColorMapId	Colormap:
MhwWgtVisual	visual;
Card32	blackPixel;
Card32	whitePixel:
Card32	transparent Pixel;
MhwWgtColor	verylightGray;
MhwWgtColor	lightGray;
MhwWgtColor	middleGray:
MhwWgtColor	darkGray;
MhwWgtColor	highlight;
MhwWgtColor	blackColor;
MhwWgtColor	whiteColor;

METHOD TABLE (set to point to the overloaded methods in derived classes):
MhwWgtError	(*delete)	(MhwWgtLook);
MhwWgtErrox	(*free)	(MhwWgtLook) ;
MhwWgtError	(*reference)	(MhwWgtLook);
Card8	(*getBorderWidth)	(MhwWgtLook, MhwWgtWidget, MhwWgtLookBorder);
MhwWgtError	(*getBorderWidth)	(MhwWgtLook, MhwWgtLookBorder, Card8);
Bool	(*isInstanceOf)	(MhwWgtLook, Int32);
MhwWgtError	(*drawBackground)	(MhwWgtLook, MhwWgtWidget, Intl6, Int16, Card16, Card16):
MhwWgtError	(*drawForeground)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawRelief)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16, MhwWgtLookRelief);
MhwWgtError	(*unDrawRelief)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16):
MhwWgtError	(*drawFocus)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16):
MhwWgtError	(*unDrawFocus)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawHighlight)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*unDrawHighlight)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawInset)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16):
MhwWgtError	(*drawOutset)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16).
MhwWgtError	(*drawSelectedBG)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16) ;
MhwWgtError	(*drawCheckSymbol)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16, Bool, MhwWgtCheckStyle):
MhwWgtError	(*drawChoiceSymbol)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawAnchor)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16, String, Card32, Int8, MhwWgtLookItemFlag, MhwWgtColor);
MhwWgtError	(*drawCross)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*unDrawCross)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawltem)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16, String. Card32, Int8, MhwWgtLookItemFlag);
MhwWgtError	(*reDrawltem)	(MhwWgtLook, MhwWgtWidget, Intl6, Int16, Card16, Card16, String, Card32, Int8, MhwWgtLookltemFlag, Bool);
MhwWgtError	(*drawSlidArrow)	(MhwWgtLook, MhwWgtWidget, Int16, Intl6, Card16, Card16, MhwWgtSlidDirection);
MhwWgtError	(*drawSlidLift)	(MhwWgtLook. MhwWgtWidget. Int16, Int16, Card16, Card16);
MhwWgtError	(*drawCursor)	(MhwWgtLook, MhwWgtWidget, Int16. Int16, Card16, Card16);
MhwWgtError	(*unDrawCursor)	(MhwWgtLook, MhwWgtWidget, Int16, Int16, Card16, Card16);
MhwWgtError	(*drawString)	(MhwWgtLook, MhwWgtWidget, Int16,
		Int16, String, Card32, Int8);
MhwWgtDimension	(*getPreferredSizeArrow)	(MhwWgtLook);
MhwWgtDimension	(*getPreferredSizeCheck)	(MhwWgtLook);
MhwWgtDimension	(*getPreferredSizeChoice)	(MhwWgtLook);
MhwWgtDimension	(*getPreferredSizeCross)	(MhwWgtLook) ;
Card8	(*getItemBorderwidth)	(MhwWgtLook) ;

[0260] (The Card8, Card16, etc. data types are aliases for number types having the indicated number of bits, e.g. Card8 is equivalent to a 'char', Card16 is equivalent to a 'short', etc.)

[0261] Each draw method is identical for each object type. For looks which require a different method for each method, or at least for certain methods, the method in the look class must identify the widget type and act accordingly.

[0262] Note the purpose of the DrawNothing() method. It simply returns OK if called. Certain features are not necessarily implemented in a given look. So that WGT does not necessarily have to test the existence of a given function, any unimplemented functions should point to this method.

[0263] Note also Mask. This is a private, read-only Boolean array where each element corresponds to one of the above methods. If an element is set to 1, then the corresponding method is redefined. Otherwise, the method is not redefined. In this way, if it wants to, WGT can find out in a single operation which methods it has to call.

[0264] The look class is used to define the interface between any look definition and WGT. WGT uses only these methods to display the required look. If additional functionality is required of a look, it can be incorporated in an extended look structure, but it is up to the application and not WGT to take these methods/parameters into account. In this way, additional attributes and methods can be added.

[0265] A derived look structure must contain all these methods and attributes, and it can also add its own. However. WGT will only take those methods defined in the MhwWgtLook structure into account.

[0266] The MhwWgtLookWgt class is now discussed.

[0267] So that existing applications do not have to be modified to remain compatible with the modified version of WGT, a basic look class, defining the look that WGT objects currently have, is created and instantiated by WGT.

[0268] It is a sub-class of MhwWgtLook and is called MhwWgtLookWgt. When this class is initialised, the values of all of the pointers in the structure are set to point at the WGT-defined methods.

[0269] This basic class contains nothing else - it simply defines the look that WGT currently provides.

FIELDS:
Card8	reliefWidth
MhwWgtColor	reliefColorWhite;
MhwWgtColor	reliefColorBlack;
Card8	focusWidth;
MhwWgtColor	focusColor;
Card8	highlightWidth;
MhwWgtColor	highlightColor;
MhwWgtColor	anchorColorBGNormal;
MhwWgtColor	anchorColorFGVisited:
MhwWgtColor	anchorColorBGCurrent:
Cardl6	mask;
Card8	reliefWidth;
MhwWgtColor	reliefColorWhite;
MhwWgtColor	reliefColorBlack;
Card8	focusWidth;
MhwWgtColor	focusColor;
Card8	highlightWidth;
MhwWgtColor	highlightColor;
MhwWgtColor	anchorColorBGNormal;
MhwWgtColor	anchorColorFGVisited;
MhwWgtColor	anchorColorBGCurrent;
MhwWgtColorMapId	colorMap;
Card32	blackPixel;
Card32	whitePixel;
Card32	transparentPixel;
MhwWgtColor	verylightGray;
MhwWgtColor-	lightGray;
MhwWgtColor	middleGray;
MhwWgtColor	darkGray:
MhwWgtColor	highlight;
MhwWgtColor	blackcblor;
MhwWgtColor	whiteColor;

METHOD TABLE:
MhwWgtError	(*setReliefWidth)	(MhwWgtLkWgt, Card8);
MhwWgtError	(*setReliefColorBlack)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setReliefColorWhite)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setFocusWidth)	(MhwWgtLkWgt, Card8);
MhwWgtError	(*setFocusColor)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setHighlightWidth)	(MhwWgtLkWgt, Card8);
MhwWgtError	(*setHighlightColor)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setAnchorColorBGNormal)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setAnchorColorFGvisited)	(MhwWgtLkWgt, MhwWgtColor);
MhwWgtError	(*setAnchorColorBGCurrent)	(MhwWgtLkWgt, MhwWgtColor) ;

[0270] With regard to the WGT initialisation, an instance of the MhwWgtLookwgt class must be created when the WGT is started. WGT will thus have access to these methods if the application does not specify a different look. The g_TheDefaultLook global variable (described below) must initially be set to point at this look.

[0271] The processes of defining new Looks and setting default Looks are now described.

[0272] WGT is not responsible for defining or instantiating new look objects. Applications must do this themselves. All look objects created must be castable in an MhwWgtLook structure. C.f. the management of Looks below.

With regard to default looks, a field:

[0273] MhwWgtLook *DefaultLook must be added to the MhwWgtContext object pointing to the instance of MhwWgtLook to be applied to any new objects created from this context. When a new WGT context is created, this field must be set to point at WgtBasicLook.

With regard to setting the default Look for a Context, a public method:

[0274] MgwWgtSetDefaultLook(MhwWgtContext, aContext, MhwWqtLook aLook) is provided to set the DefaultLook field in aContext to point at aLook.

[0275] For associating a Look with an Object, the following attribute is added to the coreAtts structure in the core class:

MhwWgtLook *Look

[0276] This attribute is thus created for each object created. Whenever a object is instantiated, Look is set to point at the DefaultLook global variable.

[0277] Two new public methods MhwWgtSetXXXAttsLook(MhwWgtWidget anObject, MhWWgtLook aLook) and MhwWgtGetXXXAttsLook(MhwWgtWidget anObject, MhwWgtLook *aLook) should be added to the core class to allow the look instance associated with the object to be changed.

[0278] The management of Looks is now discussed.

[0279] WGT does not provide any look management. In order to use a look other than the default, an application must first ensure that one or more look classes are instantiated and initialised, and then each time that it creates a new WGT object, use the MhwWgtSetCore-AttsLook() method to associate the object with the desired look. If it wishes to use a given look for all future widgets, it can use the MhwWgtSetDefaultLook() method described above.

[0280] An application wishing to use any look other than the one defined by default is responsible for creating and instantiating the look. In another embodiment of the invention, an application may download looks remotely. In this case, however, the application itself must supply the required classes, derived from MhwWgtLook.

[0281] A look must not be destroyed by the application that created it until all the widgets which use it have been destroyed. This requires the addition of a refCounter field to count the number of "clients".

[0282] This replaces free (look). The look will actually be destroyed when its refCounter field equals 0.

[0283] The WGT Module List of APIs for implementing Looks is given here:

extern MhwWgtError MhwWgtLookInitDefault	(MhwWgtLookCIass*, MhwWgtLookAtts*);
extern MhwWgtError MhwWgtLookinitClass	(Void);
extern MhwWgtError MhwWgtLookResetDefault	(MhwWgtLookClass*);
extern MhwWgtError MhwWgtLookAttsGetBorderWidthBTLR	(MhwWgtLookAtts*, card8*, CardB*, Card8*, Card8*);
extern MhwWgtError MhwWgtLookAttsGetBorderWidthBottom	(MhwWgtLookAtts*, Card8*);
extern MhwWgtError MhwWgtLookAttsGetBorderWidthLeft	(MhwWgtLookAtts*, Card8*);
extern MhwWgtError MhwWgtLookAttsGetaorderWidthRight	(MhwwgtLookAtts*, Card8*);
extern MhwWgtError MhwWgtLookAttsGetBorderWidthTop	(MhwWgtLookAtts*, Card8*);
extern MhwWgtError MhwWgtLookAttsGetDefault	(MhwWgtLookClass*, MhwWgtLookAtts*)
extern MhwWgtError MhwWgtLookAttsInit	(MhwWgtLookAtts*);
extern MhwWgtError MhwWgtLookAttsSetBorderWidthBTLR	(MhwWgtLookAtts*, Card8, Card8, Card8, Card8);
extern MhwWgtError MhwWgtLookAttsSetBorderWidthBottom	(MhwWgtLookAtts*, Card8);
extetn MhwWgtError MhwWgtLookAttsSetBorderWidthLeft	(MhwWgtLookAtts*, Card8);
extern MhwWgtError MhwWgtLookAttsSetBorderWidthRight	(MhwWgtLookAtts*, Card8);
extern MhwWgtError MhwWgtLookAttsSetBorderWidthTop	(MhwWgtLookAtts*, Card8);

[0284] The Look/LookPixmap module will now be described in more detail.

[0285] The MhwWgtLookPixmap class is derived from the MhwWgtLook class described above. Essentially it works by reconstructing the various elements of each component to create a graphical image of the required size, as described above.

[0286] These images are used for the following: backgrounds for buttons; relief (that is the border around the active zone of text areas, for example); a symbol for the Choice component; checkboxes; sliders; and slider lifts.

[0287] With reference to Figure 40, to reduce initialization time, the images are not compressed, but are stored in a special format designed to minimize as far as possible the space occupied. The colour of each pixel (2152) is described in a single byte, which is the index number (2151) of the colour in the current colourmap. Figure 40 shows an example buffer, image, containing an 4x4 image (2153).

[0288] The image (2153) in Figure 40 would be stored as follows:

[0289] The LookPixMap Image structure will now be described.

[0290] In order to identify the size of an image buffer, a structure, LookPixmaplmage, is defined including the image buffer described above, together with the width and height of the image. This structure, defined below, is used to contain the data for each graphical element.

[0291] Images can be of different sizes, although for a given type of element they will generally be the same. The central element (xxxxxC), however, is often of size 1 x 1. The MhwWgtLookPixmapAllImages structure groups together all the picture elements as shown below:

[0292] This section describes the LookPixmap module, including the LookPixmap class, which has been created to allow a set of different looks to be applied to the Web Browser.

[0293] This module contains the following source files: MhwWgtLookPixmap.h;
MhwWgtLookPixmapStruct.h; WgtLookPixmapClass.c; WgtLookPixmapPrivate.c;
MhwWgtLookPixmapImages.h; MhwWgtLookPixmapImages2.h;
MhwWgtLookPixmapImages3.h; MhwWgtLookPixmapImages4.h;
MhwWgtLookPixmaplmages5.h; and MhwWgtLookPixmaplmages6.h.

[0294] The LookPixmap Module will now be described, including details of the preferred method of creating and using LookPixmap Objects.

[0295] Any software using WGT for the creation and management of Widgets can use the LookPixmap module to provide alternative looks to the WGT widgets. For an application to use the LookPixmap look, a LookPixmap object must be created. This can be done using the following code:

MhwWgtLkWebClass	PixmapLook;
MhwWgtLkWeb	PixmapLookObject;
MhwWgtLkWebAtts	LookPixmapValues;
MhwWgtError	WgtErr;

WgtErr

= MhwWgtLkWebInitClass () ;

WgtErr

= MhwWgtLkWebAttsInit (&LookPixmapValues) ;

WgtErr

= MhwWgtLkWebInitDefault(&PixmapLook, &LookPixmapValues);

PixmapLookObject

= MhwWgtLkWebNew(&LookPixMapValues);

[0296] A method for setting the default look is now described.

[0297] An application can use a given look object by default. By default. the default look is the LookWgt object created by WGT. In order to set another default look, on condition that it has already been created as described above. the fullowing function can be used:
MhwWgtSetDefaultLook((MhwWgtLook)PixmapLookObject);
All subsequent WGT widgets created will be associated with the LookPixmap look class and not the WGT default LookWgt

[0298] An application can choose or set a look for a given type of widget, or a given widget, as will now be described.

[0299] An application can set the look for a given widget when the object is created by calling the following function just before the widget is created:
MhwWgtXXXAttsSetLook (MhwWgtXXXAtts*, MhwWgtLook);
It can also set the look of an object after creation using the following function:
MhwWgtXXXSetLook (MhwWgtXXXWidget *, MhwWgtLook);
(where xxx is the type of widget - eg LIST).

[0300] The method of using LookPixmap Images is now described.

[0301] A single LookPixmap object uses a single set of images. You can obviously change the look dramatically, simply by changing the images.

[0302] You can change the images used for a given LookPixmap object by calling the following functions:
MhwWgtLookPixmapSet Images (MhwWgtLookPixmap *, MhwWgtLookPixmapAllImages*); Sets the images used for all widgets using the specified LookPixmap object to the specified image set.
MhwWgtLookPixmapSetDefaultImages(MhwWgtLookPixmap*) Sets the images used for all widgets using the specified LookPixmap object to the default image set.

[0303] If you wish to use different images for different widgets, you must create a LookPixmap object for each set of images required. You then assign each image set to the appropriate look, and then associate each look to the appropriate widget.

[0304] The API of the LookPixmap module will now be described, with reference to Figures 39 and 41.

[0305] The following public APIs are available:

MhwWptLookPixmapSetlmages()

Prototype:

[0306] 

MhwWgtError MhwWgtLookPixmapSetImages

(MhwWgtLkWeb aLook, MhwWgtLookPixmapAllImages* someImages);

Description:

[0307] Sets the set of images used by aLook to the set of images pointed to by someImages. Parameters:

aLook

The MhwWgtLkWeb object to which to associate the images, someImages

someImages

The set of images to associate with aLook.

Returns:
MHW_WGT_SUCCESS

MhwWgtLookPixmapSetImagesID()

Prototype:

[0308] 

MhwWgtError MhwWgtLookPixmapSetImagesID (MhwWgtLkWeb aLook, Card8 anImageID);

Description:

[0309] Sets the set of images used by aLook to the set of images hard-programmed in MhwWgtLookPixMap and identified by anImageID.
Parameters:

aLook

The MhwWgtLkWeb object to which to associate the images identified by anImageID.

anlmageID

The identifier of the set of images, hard-programmed in MhwWgtLookPixmap, to associate with aLook.

Returns:
MHW_WGT_SUCCESS

MhwWgtLookPixmapSetDefaultImages()

Prototype:

[0310] 

MhwWgtError MhwWgtLookPixmapSetDefaultImages (MhwWgtLkWeb aLook);

Description:

[0311] Sets the set of images used by aLook to the set of images hard-programmed in MhwWgtLookPixmap and identified by the identifier 1.
Parameters:

aLook

The MhwWgtLkWeb object to which to associate the images identified by anlmageID.

Returns:
MHW_WGT_SUCCESS

MhwWgtLookPixmapLoadImage()

Prototype:

[0312] 

MhwWgtError MhwWgtLookPixmapLoadImage

(MhwWgtLkWeb aLook, Int32 anElementID, Int32 aWidth, Int32 aHeight, Card8* anImageBuffer);

Description:

[0313] Used to change a single image pointed to by the current MhwWgtLookPixmapAllImages structure to point at the specified image. Creates an LookPixmapImage structure and sets the current MhwWgtLookPixmapAllImages structure pointed to by aLook to point at this LookPixmapImage for the element specified by anElementID.
Parameters:

aLook

The MhwWgtLkWeb object to which to associate the images identified by anImageID.

anElementID

The identifier of the element to change.

aWidth

The width, in pixels, of the new image.

aHeight

The height, in pixels, of the new image.

anImageBuffer

The buffer containing the new image data.

Returns:
MHW_WGT_SUCCESS

LookPixmapMakeImageFromElements()

Prototype:

[0314] 

MhwWgtError LookPixmapMakeImageFromElements	(LookPixmapImage* elemN,
	LookPixmapImage* elemE,
	LookPixmapImage* elemW,
	LookPixmapImage* elemS,
	LookPixmapImage* elemNW,
	LookPixmapImage* elemE,
	LookPixmapImage* elemSW,
	LookPixmapImage* elemSE,
	LookPixmapImage* elemC, Card16 anX, Card16 aY, Card16 aWidth, Card16 aHeight, MHWWindowID aWindow, LookPixmapDrawMode aDrawMode);

Description:

[0315] Takes the nine images of elemX and draws them in the specified MHW window. The rules for constructing the image are specified by aDrawMode (currently only MHW_WGT_LIKWEB_DRAW_NORMAL exists). The final image is drawn in the window with the top left corner positioned at (anX, aY) and of size aWidth x aHeight.
If one or more of the elements have zero size (either elemXX.width or elemXX.height is zero) this element is not drawn.
Parameters:

elemN, elemE, elemW, elemS, elemNW, elemNE, elemSW, elemSE, elemC:

the image to draw at the top, right, left, bottom, top left corner, top right corner, bottom left corner, bottom right corner and middle, respectively.

anX

The x-position in the window, a Window, to draw the final image.

aY

The y-position in the window, a Window, to draw the final image.

aWidth

The width, in pixels, of the new image.

aHeight

The height, in pixels. of the new image.

aWindow

The window in which to draw the constructed image.

aDrawMode

The mode in which to construct the image.
MHW_WGT_LKWEB_DRAW_NORMAL: Puts the NW (2100), NE (2101), SW (2102) and SE (2103) elements in the four corners (2200, 2201, 2202, 2203) with no tiling. Horizontally tiles the N and S elements. Vertically tiles the W and E elements. Tiles both horizontally and vertically the C element. Although it will work for any image sizes, it is only guaranteed to correctly tile the area provided that the central area (2208) is rectangular.

Returns:
MHW_WGT_SUCCESS

[0316] The Mhw.awt Java Interface Package will now be described.

[0317] Three Java classes have been developed so that the Look mechanism defined in WGT can be exploited by java applications. These are: mhw.awt.Look; mhw.awt.WgtLook; and mhw.awt.PixmapLook.

[0318] The Look class is the abstract class corresponding to the class NMw WgtLook described above.
The WgtLook class is used to create and handle instances of the WGT class MhwWgtLookWgt.
The PixmapLook class is used to store the images used by the WgtLook class.

[0319] The Mhw.awt.PixmapLook API will now be described, beginning with details of the constructors.

PixmapLook

public PixmapLook()

[0320] Creates a new instance of a PixmapLook object, with the images initialised to the default images (ID=1)

PixmapLook

public PixmapLook(int imageID)

[0321] Creates a new instance of a PixmapLook object, with the images initialised to the images specified by imageID.

[0322] The methods will now be described.

SetImages

public void SetImages()

[0323] Set the current images for this PixmapLook object to the default (ID=I)

SetImages

public void SetImages (int imageID)

[0324] Set the current Images for this PixmapLook object to the images specified by imageID

LoadImage

[0325] 

public void	LoadImage	(int elementID,
		int width,
		int height,
		byte[] buffer)

[0326] Loads a specified image element. Each PixmapLook object has a set of (94) images associated with it. These images represent the graphic component elements as follows: 0 relnoNW; 1 relnoSW; 2 relnoNE; 3 relnoSE; 4 relnoN; 5 relnoW; 6 relnoE; 7 relnoS; 8 relnoC; 9 relfoNW; 10 relfoSW; 11 relfoNE; 12 relfoSE, 13 relfoN; 14 relfoW; 15 relfoE; 16 relfoS; 17 relfoC; 18 relhiNW; 19 relhiSW; 20 relhiNE; 21 relhiSE; 22 relhiN; 23 relhiW; 24 relhiE; 25 relhiS; 26 relhiC; 27 relfhNW; 28 relfhSW; 29 relfhNE; 30 relfhSE; 31 relfhN; 32 relfhW; 33 relfhE; 34 relfhS; 35 relfh C; 36 butnoNW; 37 butnoSW; 38 butnoNE; 39 butnoSE; 40 butnoN; 41 butnoW; 42 butnoE; 43 butnoS; 44 butnoC; 45 butfoNW; 46 butfoSW; 47 butfoNE; 48 butfoSE; 49 butfoN; 50 butfoW; 51 butfoE; 52 butfoS; 53 butfoC; 54 buthiNW; 55 buthiSW; 56 buthiNE; 57 buthiSE; 58 buthiN; 59 buthiW; 60 buthiE; 61 buthiS; 62 buthiC; 63 butfhNW; 64 butfhSW; 65 butfhNE; 66 butfhSE; 67 butfhN; 68 butfhW; 69 butfhE; 70 butfhS; 71 butfhC; 72 choice; 73 chcklno; 74 chcklse; 75 chcklfo; 76 chcklfs; 77 chck2no; 78 chck2se; 79 chck2fo; 80 chck2fs; 81 slidNeVr; 82 slidEVr; 83 slidSeVr; 84 slidSwHr; 85 slidSHr; 86 slidSeHr; 87 slidSeVrHr; 88 slidLiftNeVr; 89 slidLiftEVr; 90 slidLiftSeVr; 91 slidLiftSwHr; 92 slidLiftSHr; 93 slidLiftSeHr.
width specifies the width of the image passed.
height specifies the height of the image passed.
buffer contains the image data. This is in the form of a byte array, each byte giving the colormap index to be used for each pixel. The index used for pixel (x,y) is buffer[(y*width)+x].

MakelmageFromElements

[0327] 

public void	MakeImageFromElements	(int[] widths,
		int[] heights,
		byte[][] buffers,
		int anX,
		int aY,
		int aWidth,
		int aHeight, java.awt.Component aComponent)

[0328] Constructs an image based on 9 elements (N, E, W, S, NW, NE, SW, SE, C) and draw it on the window associated with the component aComponent with the top left corner at (anX, aY) and with size aWidth x aHeight. The image buffers are passed as a two dimensional array, one dimension giving the image number (0-8 corresponding to N, E, W, S, NW, NE, SW, SE, C) and the other containing the data. The widths and heights of each buffer are given in the arrays widths and heights.

DownloadLookDir

public java.lang.String DownloadLookDir()

[0329] Downloads a "look" directory from the MPEG stream. Returns a string containing information on each set of look images which can be downloaded separated by newlines. The line number of a title (0 to n-1) corresponds to the identifier (ImageSet) to be used with the function DownLoadLookImages(int ImageSet).

[0330] The directory is in fact a simple text file containing the string that is returned. The file path is hard coded in the source - currently /home/users/mstoddar/mhplus/util/looks/images.dir. This can be changed as appropriate. This can thus be used in the decoder to automatically download from the MPEG stream.
The format of the file is:

DownloadLookImages

public void DownloadLookImages(int ImageSet)

[0331] Downloads a new set of images from the MPEG stream, identified by the line number (0 to n-1) of one of the entries returned in DownLoadLookDir(), and attributes them to this look.

The file containing the data is in the following format:

[0332] WWWWHHHHWWWWHHHH ... a series of four byte strings (leading spaces) containing the decimal values of the widths and heights of all 94 images (in the same order as in the method LoadImage()). The data buffers for each image follow, again in the same format as LoadImage(). No alignment is made between images, the beginning of the next image starting at the byte following the previous one.

[0333] The file path is hard coded in the source - currently /home/users/mstoddar/mhplus/util/looks/images.<ImageSet>. This can be changed as appropriate. This can thus be used in the decoder to automatically download from the MPEG stream.
public void DownloadLookImages(string ImageURL)

[0334] Downloads a new set of images from the MPEG stream, identified by the URL specified, and attributes them to this look.
The file containing the data is in the format given above.

[0335] The structure of the file is given below in C syntax for clarity:

Card8 relnoNWwidth[4]	String representation of decimal value (leading spaces)
Card8 relnoNWheight[4]
Card8 relnoSWwidth[4]
Card8 relnoSWheight[4]
Card8 relnoNEwidth[4]
Card8 relnoNEheight[4]
Card8 reinoSEwidth[4]
Card8	relnoSEheight[4]
Card8	relnoNwidth[4]
Card8	relnoNheight[4]
Card8	relnoWwidth[4]
Card8	relnoWheight[4]
Card8	relnoEwidth[4]
Card8	relnoEheight[4]
Card8	relnoSwidth[4]
Card8	relnoSheight[4]
Card8	relnoCwidth[4]
Card8	relnoCheight[4]
Card8	relfoNWwidth[4]
Card8	relfoNWheight[4]
Card8	relfoSWwidth[4]
Card8	relfosWheight[4]
Card8	relfoNEwidth[4]
Card8	relfoNEheight[4]
Card8	relfoSEwidth[4]
Card8	relfoSEheight[4]
Card8	relfoNwidth[4]
Card8	relfoNheight[4]
Card8	relfoWwidth[4]
Card8	relfoWheight[4]
Card8	relfoEwidth[4]
Card8	relfoEheight[4]
Card8	relfoSwidth[4]
Card8	relfoSheight[4]
Card8	relfoCwidth[4]
Card8	relfoCheight[4]
Card8	relhiNWwidth[4]
Card8	relhiNWheight[4]
Card8	relhiSWwidth[4]
Card8	relhiSWheight[4]
Card8	relhiNEwidth[4]
Card8	relhiNEheight[4]
Card8	relhiSEwidth[4]
Card8	relhiSEheight[4]
Card8	relhiNwidth[4]
Card8	relhiNheight[4]
Card8	relhiWwidth[4]
Card8	relhiWheight[4]
Card8	relhiEwidth [4]
Card8	relhiEheight[4]
Card8	relhiSwidth[4]
Card8	relhisheight[4]
Card8	relhiCwidth[4]
Card8	relhiCheight[4]
Card8	relfhNWwidth[4]
Card8	relfhNWheight[4]
Card8	relfhSWwidth[4]
Card8	relfhSWheight[4]
Card8	relfhNEwidth[d]
card8	relfhNEheight[4]
Card8	relfhSEwidth[4]
Card8	relfhSEheight[4]
Card8	relfhNwidth[4]
Card8	relfhNheight[4]
Card8	relfhWwidth[4]
Card8	relfhWheight[4]
Card8	relfhEwidth[4]
Card8	relfhEheight[4]
Card8	relfhSwidth[4]
Card8	relfhSheight[4]
Card8	relfhCwidth[4]
Card8	relfhCheight[4]
Card8	butnoNWwidth[4]
Card8	butnoNWheight[4]
Card8	butnoSWwidth[4]
Card8	butnoSWheight[4]
Card8	butnoNEwidth[4]
Card8	butnoNEheight[4]
Card8	butnoSEwidth[4]
Card8	butnoSEheight[4]
Card8	butnoNwidth[4]
Card8	butnoNheight[4]
Card8	butnoWwidth[4]
Card8	butnoWheight[4]
Card8	butnoEwidth[4]
Card8	butnoEheight[4]
Card8	butnoSwidth[4]
Card8	butnoSheight[4]
Card8	butnoCwidth[4]
Card8	butnoCheight[4]
Card8	butfoNWwidth[4]
Card8	butfoNWheight[4]
Card8	butfoSwwidth[4]
Card8	butfoSWheight[4]
Card8	butfoNEwidth[4]
Card8	butfoNEheight[4]
Card8	butfoSEwidth[4]
card8	butfoSEheight[4]
Card8	butfoNwidth[4]
Card8	butfoNheight[4]
Card8	butfoWwidth[4]
Card8	butfoWheight[4]
Card8	butfoEwidth[4]
Card8	butfoEheight[4]
Card8	butfoSwidth[4]
Card8	butfoSheight[4]
Card8	butfoCwidth[4]
Card8	butfoCheight[4]
Card8	buthiNWwidth[4]
Card8	buthiNWheight[4]
Card8	buthiSWwidth[4]
Card8	buthiSWheight[4]
Card8	buthiNEwidth[4]
Card8	buthiNEheight[4]
Card8	buthiSEwidth[4]
Card8	buthiSEheight[4]
Card8	buthiNwidth[4]
Card8	buthiNheight[4]
Card8	buthiWwidth[4]
Card8	buthiWheight[4]
Card8	buthiEwidth[4]
Card8	buthiEheight[4]
Card8	buthiSwidth[4]
Card8	buthiSheight[4]
Card8	buthiCwidth[4]
Card8	buthiCheight[4]
Card8	butfhNWwidth[4]
Card8	butfhNWheight[4]
Card8	butfhSWwidth[4]
Card8	burfhSWheight[4]
Card8	butfhNEwidth[4]
Card8	butfhNEheight[4]
Card8	butfhSEwidth[4]
Card8	butfhSEheight[4]
Card8	butfhNwidth[4]
Card8	butfhNheight[4]
Card8	butfhWwidth[4]
Card8	butfhWheight[4]
Card8	butfhEwidth[4]
Card8	butfhEheight[4]
Card8	butfhSwidth[4]
Card8	butfhSheight[4]
Card8	butfhCwidth[4]
Card8	butfhCheight[4]
Card8	choicewidth[4]
Card8	choiceheight[4]
Card8	chcklnowidth[4]
Card8	chckinoheight[4]
Card8	chcklsewidth[4]
Card8	chcklseheight[4]
Card8	chcklfowidth[4]
Card8	chcklfoheight[4]
Card8	chcklfswidth[4]
Card8	chcklfsheight[4]
Card8	chck2nowidth[4]
Card8	chck2noheight[4]
Card8	chck2sewidth[4]
Card8	chck2seheight[4]
Card8	chck2fowidth[4]
Card8	chck2foheight[4]
Card8	chck2fswidth[4]
Card8	chck2faheight[4]
Card8	slidNeVrwidth[4]
Card8	slidNeVrheight[4]
Card8	slidEVrwidth[4]
Card8	slidEVrheight[4]
Card8	slidSeVrwidth[4]
Card8	slidSeVrheight[4]
Card8	slidSwHrwidth[4]
Card8	slidSwHrheight[4]
Card8	slidSHrwidth[4]
Card8	slidSHrheight[4]
Card8	slidSeHrwidth[4]
Card8	slidSeHrheight[4]
Card8	slidSeVrHrwidth[4]
Card8	slidSeVrHrheight[4]
Card8	slidLiftNeVrwidth[4]
Card8	slidLiftNeVrheight[4]
Card8	slidLiftEVrwidth[4]
Card8	slidLiftEVrheight[4]
Card8	slidLiftSeVrwidth[4]
Card8	slidLiftSeVrheight[4]
Card8	slidLiftSwHrwidth[4]
Card8	slidLiftSwHrheight[4]
Card8	slidLiftSHrwidth[4]
Card8	slidLiftSHrheight[4]
Card8	slidLiftSeHrwidth[4]
Card8	slidLiftSeHrheight[4]
Card8	RelnoNWbuffer[width x height]
Card8	RelnoSWbuffer[width x height]
Card8	RelnoNEbuffer[width x height]
Card8	RelnoSEbuffer[width x height]
Card8	RelnoNbuffer[width x height]
Card8	RelnoWbuffer[width x height]
Card8	RelnoEbuffer[width x height]
Card8	RelnoSbuffer[width x height]
Card8	RelnoCbuffer[width x height]
Card8	RelfoNWbuffer[width x height]
Card8	RelfoSWbuffer[width x height]
Card8	RelfoNEbuffer[width x height]
	Card8 ReltoSEbuffer[width x height]
Card8	RelfoNbuffer[width x height]
Card8	RelfoWbuffer[width x height]
Card8	RelfoEbuffer[width x height]
Card8	RelfoSbuffer[width x height]
Card8	RelfoCbuffer[width x height]
Card8	RelhiNWbuffer[width x height]
Card8	RelhiSWbuffer[width x height]
Card8	RelhiNEbuffer[width x height]
Card8	RelhiSEbuffer[width x height]
Card8	RelhiNbuffer[width x height]
Card8	RelhiWbuffer[width x height]
Card8	RelhiEbuffer[width x height]
Card8	RelhiSbuffer[width x height]
Card8	RelhiCbuffer[width x height]
Card8	RelfhNWbuffer[width x height]
Card8	RelfhSWbuffer[width x height]
Card8	RelfhNEbuffer[width x height]
Card8	RelfhSEbuffer[width x height]
Card8	RelfhNbuffer[width x height]
Card8	RelfhWbuffer[width x height]
Card8	RelfhEbuffer[width x height]
Card8	RelfhSbuffer[width x height]
Card8	RelfhCbuffer[width x height]
Card8	ButnoNWbuffer[width x height]
Card8	ButnoSWbuffer[width x height]
Card8	ButnoNEbuffer[width x height]
Card8	ButnoSEbuffer[width x height]
Card8	ButnoNbuffer[width x height]
Card8	ButnoWbuffer[width x height])
Card8	ButnoEbuffer[width x height]
Card8	ButnoSbuffer[width x height]
Card8	ButnoCbuffer[width x height]
Card8	ButfoNWbuffer[width x height]
Card8	ButfoSWbuffer[width x height]
Card8	ButfoNEbuffer[width x height]
Card8	ButfoSEbuffer[width x height]
Card8	ButfoNbuffer[width x height]
Card8	ButfoWbuffer[width x height]
Card8	ButfoEbuffer[width x height]
Card8	ButfoSbuffer[width x height]
Card8	ButfoCbuffer[width x height]
Card8	ButhiNWbuffer[width x height]
Card8	ButhiSWbuffer[width x height]
Card8	ButhiNEbuffer[width x height]
Card8	ButhiSEbuffer[width x height]
Card8	ButhiNbuffer[width x height]
Card8	ButhiWbuffer[width x height]
Card8	ButhiEbuffer[width x height]
Card8	ButhiSbuffer[width x height]
Card8	ButhiCbuffer[width x height]
Card8	ButfhNWbuffer[width x height]
Card8	ButfhSWbuffer[width x height]
Card8	ButfhNEbuffer[width x height]
Card8	ButfhSEbuffer[width x height]
Card8	ButfhNbuffer[width x height]
Card8	ButfhWbuffer[width x height]
Card8	ButfhEbuffer[width x height]
Card8	ButfhSbuffer[width x height]
Card8	ButfhCbuffer[width x height]
Card8	Choicebuffer[width x height]
Card8	chck1nobuffer[width x height]
Card8	chck1sebuffer[width x height]
Card8	chck1fobuffer[width x height]
Card8	chck1fsbuffer[width x height]
Card8	chck2nobuffer[width x height]
Card8	chck2sebuffer[width x height]
Card8	chck2fobuffer[width x height]
Card8	chck2fsbuffer[width x height]
Card8	slidNeVrbuffer[width x height]
Card8	slidEVrbuffer[width x height]
Card8	slidSeVrbuffer[width x height]
Card8	slidSwHrbuffer[widch x height]
Card8	slidSHrbuffer[width x height]
Card8	slidSeHrbuffer[width x height]
Card8	slidSeVrHrbuffer[width x height]
Card8	slidLiftNevrbuffer[width x height]
Card8	slidLiftEVrbuffer[width x height]
Card8	slidLiftSeVrbuffer[width x height]
Card8	slidLiftSwHrbuffer[width x height]
Card8	slidLiEtSHrbuffer[width x height]
Card8	slidLiftSeHrbuffer[width x height]

[0336] For example:

	Width		Height		Width		Height
0000000		8		8		8		8
0000020		8		8		8		8
0000040		8		8		8		8
0000060		8		8		8		8
0000100		8		8		8		8
0000120		8		8		8		8
0000140		8		8		8		8
0000160		8		8		8		8
0000200		8		8		1		1
0000220		8		8		8		8
0000240		8		8		8		8
0000260		8		8		8		8
0000300		8		8		8		8
0000320		1		1		8		8
0000340		8		8		8		8
0000360		8		8		8		8
0000400		8		8		8		8
0000420		8		8		1		1
0000440		8		8		8		8
0000460		8		8		8		8
0000500		8		8		8		8
0000520		8		8		8		8
0000540		1		1		8		8
0000560		8		8		8		8
0000600		8		8		8		8
0000620		8		8		8		8
0000640		8		8		1		1
0000660		8		8		8		8
0000700		8		8		8		8
0000720		8		8		8		8
0000740		8		8		8		8
0000760		1		1		8		8
0001000		8		8		8		8
0001020		8		8		8		8
0001040		8		8		8		8
0001060		8		8		1		1
0001100	1	6	1	6	1	6	1	6
0001120	1	6	1	6	1	6	1	6
0001140	1	6	1	6	1	6	1	6
0001160	1	6	1	6	1	6	1	6
0001200	1	6	1	6		8		8
0001220		8		8		8		8
0001240		8		8		8		8
0001260		8		8		1		1
0001300		2		2		2		2
0001320		2		2		2		2
0001340		2		2		2		2

Start of buffer 1 data. (relnoNW) (8x8 bytes)
0001360	\0	\0	\0	\0	\0	266	004	004	\0	\0	\0	266	\n	\r	\r	\r
0001400	\0	\0	\n	\r	017	\r	\v	001	\0	266	\r	017	\r	001	001	001
0001420	\0	\n	017	\r	001	001	001	001	265	\r	\r	001	001	001	001	001
0001440	004	\r	\v	001	001	001	001	001	004	\v	001	001	001	001	001	006

Start of buffer 2 data. (relnoSW) (8x8 bytes)
0001460	004	004	263	\0	\0	\0	\0	\0	\r	\r	\v	004	\a	\0	\0	\0
0001500	001	001	001	270	004	262	\0	\0	001	001	001	001	\n	004	004	\0
0001520	001	001	001	001	001	\n	\a	\0	001	001	001	001	001	270	\L	265
0001540	001	001	001	001	001	270	\t	\a	006	001	001	001	001	270	\C	006

Start of buffer 3 data. (relnoNE) (8x8 bytes)
0001560	004	\v	001	001	001	001	001	006	\b	001	001	001	001	001	001	001
0001600	006	\n	001	001	001	001	001	001	\0	265	\n	001	001	001	001	001
0001620	\0	006	\t	\rL	001	001	001	001	\0	\0	261	\t	\n	\n	\n	\n
0001640	\0	\0	\0	006	022	265	265	\t	\0	\0	\0	\0	\0	\a	006	006

Start of buffer 4 data. (relnoSE) (8x8 bytes)
0001660	\r	001	001	001	001	270	\t	006	001	001	001	001	001	270	\t	006
0001700	001	001	001	001	001	\n	265	261	001	001	001	001	\n	266	261	\0
0001720	001	001	001	\n	266	\b	261	\0	270	270	004	266	\b	261	\0	\0
0001740	\t	\t	\b	261	261	\0	\0	\0	006	006	261	\0	\0	\0	\0	\0

etc.

reDrawAll

public void reDrawAll()

[0337] Finds the widget with the focus, then the parents until no more. Top window then set to invisible and visible again. Then the whole window should be redrawn.

[0338] The various methods described above for displaying one or more graphical objects, for navigating between a plurality of such objects, or for receiving input from the user may equally be applied to other areas primarily, but not exclusively, within the context of the reception of broadcasts from a broadcast supplier. In general, any functionality of a set-top box involving visual interaction with a user may employ such methods.

[0339] For example, a navigable chain of icons, possibly with subchains attached, could be employed in a home shopping application, to allow the user to display articles, view prices, place orders and otherwise interact with the application. The graphical object used to place an order might, when highlighted, automatically 'flip' in the manner described above between the symbol to buy (for example, a dollar sign, $) and text representing the amount spent so far, or the word "buy" in the language of the subscriber. Alternatively, or in addition, a graphical object containing the word 'buy' in the subscriber's language, could appear whenever the 'buy' icon is selected, and provide a branch for any sub-chains to 'hang off'.

[0340] The 'buy' icon in the above example might be placed next to an icon which, when clicked, views the list of purchases made so far, and another icon which, when clicked, sets delivery options for the products just bought, so as to provide a logical sequence of icons in the chain which the user can navigate. When the 'buy' icon is selected, a sub-chain could appear with various subsidiary options, which might include different credit plans in the case of more expensive items. Any text information required from the user, such as a street address for delivery, could be entered with the virtual keyboard.

[0341] In an electronic programme guide, similar methods could be employed, for interactively browsing and displaying different channels, themes and times and dates. Further customisation might be possible for re-arranging the graphic options in the chain according to the user's preferences; in the case of a chain of channels, the user's preferred channels could be grouped at the head of the chain. Such a preference could be indicated by the user, or deduced by the programme.

[0342] Other applications for the methods described above include on-line catalogues, news and weather services on demand, games, and general administration of the set-top box (managing its configuration, etc.). In the case of games, the head/tail flip-flop effect could be used to provide in-game animations without necessarily requiring additional methods to be written, and the virtual keyboard could be used as an alternative form of controller for more advanced types of game.

[0343] It should also be appreciated that all methods of interaction using a remote control, as described herein, may be substituted or supplemented by the use of a mouse (or other directional controller, such as a rollerball or joystick) and/or keyboard (or other device having a plurality of keys), either by simulating the buttons of a remote control (for example using the numbers 0-9; the arrow keys, and the return key on a keyboard) or directly (for example using the mouse to click on buttons, and the keyboard to enter text directly instead of using the virtual keyboard).

[0344] The Virtual Keyboard described above may be implemented on any device having a plurality of keys, such as a games machine or a mobile telephone, for example. In the latter case, the virtual keyboard could be displayed substantially as described on the screen of the telephone (on phones with a sufficiently large display), or in a compressed form (on phone with smaller displays). Such compression of the virtual keyboard might entail showing only one number block of characters at a time, preferably with a suggestion of the characters or types of characters which might be accessed by pressing the left, right, up and/or down keys (or their equivalents, for example in the case of roller-type directional controllers). The compressed virtual keyboard may be used in other applications, particularly where there is little space available to display the keyboard.

[0345] The term 'check box' may refer to a graphical object of any shape, for example circular, which is able to display different states, preferably two states corresponding to 'checked' and 'unchecked', but possibly more than two states, and which may alter its state in a consistent fashion when clicked or selected by the user. The 'checked' state may be indicated by a tick, cross or other embellishment on the box.

[0346] For ease of reference, the terms below used herein have the following preferred meanings:

HTML: HyperText Markup Language, a language describing the documents which are interchanged on the Internet. The document may include references to sites, formatting information, sound and pictures, etc.

HTTP: HyperText Transport Protocol, a protocol for communicating between Internet servers holding HTML documents and a navigation application, which displays the HTML documents.

MPEG-2: Motion Picture Expert Group, a method of coding animated images and sound in realtime.

PPP: Point-to-Point Protocol, a distance access communications protocol allowing two computers to be networked via a modem.

PROXY SERVER: An application located on the server which allows secure Internet connections, and which also buffers HTTP and FTP requests.

SESSION: An instance of a type of connection or of an application in memory at a given point in time.

URL: Uniform Resource Locator, an address used to locate a file or resources on the Internet. A link to a site designates the address of the resource contained in the web page.

WWW: World Wide Web, Internet network using local or remote documents. A web document is a web page, and the links in the page allow navigation between different pages and between different subjects, regardless of whether situated on a local or remote network.

GUI: Graphical User Interface.

WGT: Widget Toolkit.

[0347] It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

[0348] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. In any or all of the aforementioned, certain features of the present invention have been implemented using computer software. However, it will of course be clear to the skilled man that any of these features may be implemented using hardware or a combination of hardware and software. Furthermore, it will be readily understood that the functions performed by the hardware, the computer software, and such like are performed on or using electrical and like signals.

[0349] Features which relate to the storage of information may be implemented by suitable memory locations or stores. Features which relate to the processing of information may be implemented by a suitable processor or control means, either in software or in hardware or in a combination of the two.

[0350] In any or all of the aforementioned, the invention may be embodied in any, some or all of the following forms: it may be embodied in a method of operating a computer system; it may be embodied in the computer system itself; it may be embodied in a computer system when programmed with or adapted or arranged to execute the method of operating that system; and/or it may be embodied in a computer-readable storage medium having a program recorded thereon which is adapted to operate according to the method of operating the system.

[0351] As used herein throughout the term "computer system" may be interchanged for "computer", "system", "equipment", "apparatus", "machine" and like terms.

[0352] Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

[0353] The Applicant hereby declares, for the avoidance of doubt that he claims copyright in the attached drawings.

Claims

1. A method of controlling the appearance of an object-oriented widget (430; 500) in a graphical user interface, comprising:

defining a look object and

associating the took object with the widget (430; 500);

wherein the look object includes code or code parameters determining how the widget (430; 500) is displayed, and
wherein the look object defines the appearance of the widget (430; 500),
characterised in that the look object includes an update counter whose value is updated when the look object is re-defined or modified.

2. A method according to claim 1 wherein the look object is defined by object-oriented program code.

3. A method according to claim 1 wherein the widget includes an attribute identifying the look object associated with the widget (430; 500).

4. A method according to claim 1 further comprising modifying the appearance of the widget (430; 500) by redefining or modifying the look object or by associating a different look object with the widget (430; 500).

5. A method according to claim 1, further comprising controlling the appearance of a plurality of widgets (430; 500) in a graphical user interface by associating the look object with the plurality of widgets (430; 500).

6. Apparatus (13) for controlling the appearance of on object-oriented widget (430; 500) in a graphical user interface, comprising:

means (220) for defining a look object; and

means (220) for associating the look object with the widget (430; 500);

wherein the look object includes code or code parameters determining how the widget (430; 500) is displayed, and
wherein the look object defines the appearance of the widget (430: 500),
characterised in that the look object includes an update counter whose value is updated when the look object is re-defined or modified.

Ansprüche

1. Verfahren zur Steuerung des Aussehens eines objektorientierten Trickfensters (430; 500) bei einer graphischen Benutzerschnittstelle, die beinhaltet:

Bestimmung eines Betrachtungsgegenstands; und

Verknüpfung des Betrachtungsgegenstands mit dem Trickfenster (430; 500);

wobei der Betrachtungsgegenstand einen Kode oder Kodeparameter enthält, die bestimmen, wie das Trickfenster (430; 500)dargestellt wird und
wobei der Betrachtungsgegenstand die Erscheinung des Trickfensters (430; 500) bestimmt,
dadurch gekennzeichnet, dass
der Betrachtungsgegenstand ein Aktualisierungszählwerk aufweist, dessen Wert aktualisiert wird, wenn der Betrachtüngsgegenstand neu definiert oder verändert wird.

2. Verfahren nach Anspruch 1, wobei der Betrachtungsgegenstand durch einen objektbezogenen Programmkode bestimmt wird.

3. Verfahren nach Anspruch 1, wobei das Trickfenster ein Attribut zur Kennzeichnung des Betrachtungsgegenstands beinhaltet, das mit dem Trickfenster (430; 500) verknüpft ist.

4. Verfahren nach Anspruch 1, das ferner die Veränderung der Erscheinung des Trickfensters (430; 500) durch Neudefinition oder Veränderung des Betrachtungsgegenstands, oder durch Verknüpfung eines anderen Betrachtungsgegenstands mit einem Trickfenster (430; 500) beinhaltet.

5. Verfahren nach Anspruch 1, das ferner die Steuerung des Aussehens einer Vielzahl von Trickfenstern (430; 500) in einer graphischen Benutzerschnittstelle beinhaltet, durch Verknüpfung des Betrachtungsgegenstands mit der Vielzahl von Trickfenstern (430; 500).

6. Vorrichtung (13) zur Steuerung des Aussehens eines objektorientierten Trickfensters (430; 500) in einer graphischen Benutzerschnittstelle, die beinhaltet:

Mittel (220) zur Bestimmung eines Betrachtungsgegenstands; und

Mittel (220) zur Verknüpfung des Betrachtungsgegenstands mit dem Trickfenster (430; 500);

wobei der Betrachtungsgegenstand einen Kode oder Kodeparameter beinhaltet, die bestimmen, wie das Trickfenster (430; 500) dargestellt wird, und
wobei der Betrachtungsgegenstand das Aussehen des Trickfensters (430; 500) bestimmt,
dadurch gekennzeichnet, dass
der Betrachtungsgegenstand ein Aktualisierungszählwerk beinhaltet, dessen Wert aktualisiert wird, wenn der Betrachtungsgegenstand neu definiert oder verändert wird.

Revendications

1. Méthode de contrôle de l'apparence d'un gadget orienté objet (430 ; 500) dans une interface utilisateur graphique, comprenant :

la définition d'un objet d'aspect ; et

l'association, de l'objet d'aspect au gadget (430 ; 500) ;

dans laquelle l'objet d'aspect inclut du code ou des paramètres de code déterminant la façon dont le gadget (430 ; 500) s'affiche, et
dans laquelle l'objet d'aspect définit l'apparence du gadget (430 ; 500),
caractérisée en ce que l'objet d'aspect inclut un compteur de mise à jour dont la valeur est mise à jour lorsque l'objet d'aspect est redéfini ou modifié.

2. Méthode selon la revendication 1 dans laquelle l'objet d'aspect est défini par du code de programme orienté objet.

3. Méthode selon la revendication 1 dans laquelle le gadget inclut un attribut identifiant l'objet d'aspect associé au gadget (430 ; 500).

4. Méthode selon la revendication 1 comprenant en outre la modification de l'apparence du gadget (430 ; 500) en redéfinissant ou en modifiant les objets d'aspect ou en associant un objet d'aspect différent au gadget (430 ; 500).

5. Méthode selon la revendication 1 comprenant en outre le contrôle de l'apparence d'une pluralité de gadgets (430 ; 500) dans une interface utilisateur graphique en associant l'objet d'aspect à la pluralité de gadgets (430 ; 500).

6. Appareil (13) de contrôle de l'apparence d'un gadget orienté objet (430 ; 500) dans une interface utilisateur graphique, comprenant :

des moyens (220) pour définir un objet d'aspect ; et

des moyens (220) pour associer l'objet d'aspect au gadget (430 ; 500) ;

dans lequel l'objet d'aspect inclut du code ou des paramètres de code déterminant la façon dont le gadget (430 ; 500) s'affiche , et
dans lequel l'objet d'aspect définit l'apparence du gadget (430 ; 500),
caractérisé en ce que l'objet d'aspect inclut un compteur de mise à jour dont la valeur est mise à jour lorsque l'objet d'aspect est redéfini ou modifié.

Drawing